Bergaya F. Handbook of Clay Science

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Handbook of Clay Science

Edited by F. Bergaya, B.K.G. Theng and G. Lagaly

Developments in Clay Science, Vol. 1

1163

Chapter 15

HISTORY OF CLAY SCIENCE: A YOUNG DISCIPLINE

F. BERGAYA

, G. LAGALY

AND K. BENEKE

CRMD, CNRS-Universite

d’Orle

ans, F-45071 Orle

ans Cedex 2, France

Institut fu

r Anorganische Chemie, Universita

t Kiel, D-24118 Kiel, Germany

The contents of this handbook attest to the great diversity of clays and clay

minerals in terms of their structures, properties, and practical applications. Clays

were known and used since antiquity but yet remain essential to the synthesis and

development of modern materials, such as clay-polyme r nanocomposites (see Chap-

ter 10.3). However, clay science (i.e., the scientiﬁc study of clay) is a relatively young

discipline, having begun only about a century ago. Many factors contribute to the

rapid development of clay science over the past 100 years. Among these are the

development of analytical and instrumental techniques, enhanced clay production,

and increased industrial applications (Grim, 1988; Konta, 1995, 2000; Bergaya et al.,

2001).

15.1. DEVELOPMENT OF CLAY SCIENCE

15.1.1. Early Studies

Geologists were the ﬁrst to refer to the ﬁnely divided particles in sediments as clay

although the true nature and properties of this material were large ly unknown. For

instance, Jean Jacques The

ophile Schlo

sing (1824–1919) fractionated clay by sedi-

mentation and described the properties of the various fractions (Schlo

sing, 1874). He

also showed that nitriﬁcation was a biological process because the production of

nitrate was inhibited by chloroform vapour. One of the important applications of

this ﬁnding was the treatment of sewage. The Swedish chemist and soil scientist

Albert Mauritz Atterberg (1846–1916) studied the ﬂocculation behaviour of different

soil fractions obtained by sedimentation (Atterberg, 1905, 1910). The Atterberg

technique is still widely used for separating clays and clay minerals into particle size

fractions (see Chapter 5).

Agronomists also used particle size as a criterion for clay identiﬁcation although

the chemical and structural properties of the material were not well understood.

DOI: 10.1016/S1572-4352(05)01043-3

Until the middle of the 19th century the only tools available for the study of clays

were the optical microscopy and chemical analysis. Clays were considered to be

‘colloidal complexes’ of amorphous materials with properties that were typical of

colloidal substances (Jasmund, 1991). Interestingly, the ﬁrst publication by Robert

Wilhelm Bunsen (1811–1899) was concerned with the occurrence of allophane in a

plastic clay (Bunsen, 1834). Jakob Maarten van Bemmelen (1830–1911) considered

clays to be mixtures of aluminium and silicon oxides (van Bemmelen, 1877, 1878,

1888). The idea of chemical bonding between these oxides was not developed until

the following decades when crystalline particles were observed by microscopy. The

amorphous fraction soluble in hydrochlori c acid was referred to as Allophanton

(from German ton, clay), while the crystalline fraction was called Kaolinton

(Jasmund, 1991). Henri Louis Le Chaˆ telier (1850–1936) used thermal dehydration to

study clays , observing that water was desorbed at distinct temperatures, typical of

crystalline materials (Le Chaˆ telier, 1887) (see Chapter 12.10). Advances in optical

microscopy enabled an increasing number of clay minerals to be identiﬁed (Ross and

Shannon, 1925, 1926; Ross and Kerr, 1931a, 1931b, 1934).

The electrophoretic mobility of clay particles (Reuss, 1809) was ﬁrst described by

Ferdinand Fiodorovich Reuss (1778–1852). In his 35th letter, describing the relation

between chemistry and agriculture, Justus von Liebig (1803–1873) stressed the role of

clay minerals in providing soils with essential nutrients for plant growth, especially

following lime addition. He also described the ‘thickening’ of common clays

(To

pferton and Pfeifenerde) by addition of calcium carbonate and the gradual re-

placement of the alkali ions from the clay (von Liebig, 1858, 1865; Lagaly, 2002).

Later, Atterberg (1910, 1911) described the plasticity of clays (see Chapter 5). In

explanation, Le Chaˆ telier suggested that the plate-like particles of clay adhered like

cards when thrown on a table, and thus was the ﬁrst to have used the term ‘house-

of-cards’ (Salmang, 1927). In this connection, we should also mention that Schalek

and Szegvary (1923a, 1923b) were the ﬁrst to describe thixotropy (see Chapter 5), an

important phenomenon in clay application (Reitsto

tter, 1954).

In 1852 John Thomas Way (1820–1883) described the base exchange capacity of

soils which, at that time, was considered to be related to the presence of amorphous

materials (Way, 1852). Even Lemberg (1876), more than 20 years later, assumed that

this capacity arose from newly formed very ﬁnely divided zeolitic complexes. The

interpretation of base exchange as a cation exchange process, as we now know, goes

back to van Bemmelen. Besides recognising many important properties of clays, van

Bemmelen (1877, 1878, 1888, 1910) determined the adsorption capacity of many

agricultural soils, and gave the ﬁrst description of cation exchange. He was also the

founder of the theory of solut e-solid adsorption.

The ﬁrst repo rt on clay resources was that by Ries (1920) who used a petrographic

microscope to identify some physical properties of clays, such as plasticity, shrink-

age, and ﬁring behaviour. After 1920, several groups in Sweden (Hadding, 1923),

We thank Ewa Serwicka and Krzysztof Bahranowski (Krakow) for this reference.

Chapter 15: History of Clay Science: A Young Discipline1164

Germany (Rinne, 1924), and the USA (Ross and Shannon, 1925, 1926; Ross and

Kerr, 1931a, 1931b, 1934) investigated clays and clay minerals using chemical ana-

lysis, optical microscopy, and X-ray diffraction (XRD). In Germany, Correns (1929,

1933, 1936) studied clay minerals in sediments.

Only a few textb ooks on clay science wer e published up to the middle of the 20th

century. The ﬁrst German text, entitled Die Tone (‘‘Clays’’) by Paul Rohland

(1866–1916) was published in 1909 (Rohland, 1909). The textbook on soil colloids by

Ehrenberg (1915) also contained a section on clays. The second textbook in German

by Karl Jasmund (1913–2003) was published in 1951 (Jasmund 1951). In 1953,

Ralph E. Grim publis hed his famous book Clay Mineralogy, followed by Applied

Clay Mineralogy in 1962 (Grim, 1953, 1962). The ﬁrst edition of An Introduction to

Clay Colloid Chemistry by H. van Olphen came out in 1963 (Van Olphen, 1963).

15.1.2. XRD: An Essential Tool for Clay Mineral Research

Three Nobel prizes were awarded in relation to the discovery of X-ray radiation and

its application to elucidating clay mineral structures. In 1901 Wilhelm Conrad

ntgen (1845–1923) received the physics Nobel prize for the discove ry of X-rays

(Ro

ntgenstrahlen in German) (Ro

ntgen, 1895), followed in 1914 by Max von Laue

(1879–1960) for XRD (Friedrich et al., 1912), and by Linus Pauling (1901–1994) who

won the Nobel prize for chemi stry in 1954, and for peace in 1962 (Pauling, 1930a,

1930b). The ﬁrst X-ray powder diffraction data on clay minerals, obtained with the

Debye–Scherrer technique, were published by Assar Robert Hadding (1886–1962) in

1923 and Friedrich Rinne (1863–1933) in 1924. In 1956, Karl Jasmund developed a

special camera (Texturkamera) for the rapid investigation of clay minerals based on

the intensity enhancement of the basal reﬂections by texture.

Pauling (1930a, 1930b) was the ﬁrst to determine the structure of micas and

related materials, providing the basis for the elaboration of many other phyllosilicate

structures. In 1932 John Walter Gruner (1890–1981) proposed the structure of ka-

olinite (Gruner, 1932). A year later, Ulrich Hofmann (1903–1986), Kurd Endell

(1887–1945) and Diederich Wilm elucidated the atomic arrangement, interlayer ex-

pansion (innerkristalline Quellung), and swelling properties, of montmorillonite

(Endell et al., 1933; Hofmann et al., 1933). Hofmann et al. (1934) also studied a

montmorillonite sample from Montmorillon (France) together with many other clay

mineral species. Mehmel (1935) investigated the structure of halloysite and meta-

halloysite. Later Hendricks and Teller (1942) elaborated the theory of XRD for

interstratiﬁed minerals.

15.1.3. Other Useful Tools for Clay Mineral Research

Other instrumental techniques, besides optical microsco py and XRD, were devel-

oped in the 1930s. One of these was differential thermal analysis (DTA), providing

insight into the physical and chemical changes that occurred during heating. The

15.1. Development of Clay Science 1165

changes observed by ceramists were especially useful to understanding clay mineral

structures. The new phases developed during heating were further identiﬁed by

XRD. Another powerful tool was electron microscopy, revealing the shape and

morphology of clay mineral particles. von Ardenne et al. (1940) obtained the ﬁrst

electron micrographs of clay minerals.

15.1.4. Importance of Commercial Bentonite Production

The commercial production of bentonite played a major role in the growth of clay

science. It was Knight (1898) who suggested the name ‘bentonite’ for a clay-like

material with soapy properties from Fort Benton, Mon tana, USA. Hewett (1917)

showed that this clay was formed by in-situ alteration of volcanic ash. The com-

mercial production of the Wyoming deposits in the USA began in the 1920s and in

Europe about 10 years later, ﬁrst in Bavaria (Germany), and then in many other

countries. An important step was the modiﬁcation of bentonites with soda to give

alkali- or soda-activated bentonites (Hofmann and Endell, German Patent 1934,

British Patent 1935; Hofmann, 1976). Soda-activation, introduced by Hofmann,

transforms German bentonites into materials similar to their Wyoming counterparts

(Beneke and Lagaly, 2002a). The industrial production of bentonites in raw or

modiﬁed form is still very important (see Chapter 10.3).

15.1.5. Clay Research and Applications

Basic research into the atomic structures and surface properties of clay minerals

together with improvements in instrumental techniques (e.g., XRD, infrared spec-

troscopy, DTA), and modiﬁcation of raw clays (by acid-, soda-, and organo-

activation) greatly advanced clay science and clay mineral technology. Increased

bentonite production and several particular applications also led to a ﬂood of clay

research since the beginning of the 20th century.

A. Bleaching Earth

Natural bleaching earth (fuller’s earth) was used since antiquity for degreasing and

thickening of cloth (Siddiqui, 1968; Robert son, 1986; Novelli, 2000; Beneke and

Lagaly, 2002b). Bleaching earth is usually produced by reacting bentonites with

hydrochloric acid (see Chapters 7.1 and 10.1). The ﬁrst industrial plant for the

production of bleaching earth (Pﬁrschinger Mineralwerke) was erected in 1906 at

Kitzingen, Germany. Not long afterward Tonwerke Moosburg (now Su

d-Chemie),

Germany, produced a similar product. This was marketed as ‘Tonsil’, a name that is

still being used (Bene ke and Lagaly, 2002b).

B. Clays as Catalysts

Until the 1920s, crude oils were reﬁned by distillation. Catalytic conversion, using

acid-activated bentonite (‘Houdry process’) was introduced in 1937 (Hettinger, 1991).

Chapter 15: History of Clay Science: A Young Discipline1166

A few years later this catalyst was replaced by acid-activated kaolinite, and in the

1950s by ‘base-activated kaolinite’ (i.e., zeolites A and/or X). The advent of synthetic

zeolites spelt the demise of clays for petroleum reﬁning. Renewed interest in clay

catalysis emerged in the 1970s due to the development of pillared clays (see Chapter

7.5). The accumulated information and knowledge about zeolites advanced our un-

derstanding of clay mineral properties but the reverse is also true (Fripiat, 1995).

Clays (raw, activated, and pillared) are being used as heterogeneous catalysts in

many organic reactions (see Chapter 10.2). Clays might also served as catalysts in

processes related to the origin and development of life on earth (see Chapter 7.4).

C. Clays in Engineering

Geotechnical problems encountered during construction of the Chicago subway (in

1940) convinced engineers—who performed many tests but could not predict the

outcome—that basic knowledge of clay properties was essential to understanding the

clay behaviour. Similar problems arose in other large cities like London, Paris, San

Paulo, and Mexico City that are built on soft soil materials. The relevance of clay

science to civil engineering is further discus sed in Chapter 10.1.

D. Organoclays

The importance of interdiscip linary research was emphasised during the meeting

celebrating the 5th anniversary of the foundation of Chicago University in 1942.

Symposia on various frontiers of science were organised. The department of geology

held a symposium on clay mineralogy, pointing out the significance of this discipline

to geology. The meeting also showed the broad utility of bentonites, and a technical

guidance committee was established. John W. Jordan (1912–2001), who pioneered

research into organophilic bentonites, became the ﬁrst fellow of this committee

(Jordan, 1949a, 1949b; Jordan et al., 1950; Jordan and Williams, 1954).

15.1.6. Clay Research after World War II

The development of clay science since 1930 was described in detail by Ko

ster (1994)

and Konta (1995, 2000). The ﬁve aspects that contributed to the advancement of clay

science and the practical applications of clays are as follows:

(i) Progress in analytical and instrumental techniques. These techniques are con-

stantly being improved, and often revisited. New techniques are developed and /

or applied, including NMR, Raman, Neutron, and Mo

ssbauer spectroscopy,

SEM, ESEM, AFM, controlled rate thermal analysis (CRTA), plasma and laser

techniques, and ﬁnally computer modelling. Very useful information is gained

from the simultaneo us application of different techniques on the same sample

and under the same conditions ( Annabi-Bergaya, 1978, 1982).

(ii) Coupling the macroscopic behaviour of clay minerals to their nano-, micro-, and

mesoscopic prop erties as already remarked on in previous chapters of this

15.1. Development of Clay Science 1167

handbook. Nevertheless, more attention should be paid to this aspect than was

the case, particularly in civil engineering.

(iii) Development of novel clay-based materials, such as pillared clays, special po-

rous clays , inorganic/organic clay hybrids, clay-polymer nanocomposites, and

clay ﬁlms (using layer-by-layer deposition and Langmuir–Blodgett techniques).

These materials are the basis for a great diversity of modern applications as well

as optical and electronic devices (see Chapters 3, 5, 7.3, 7.5, 10.3, 11.1). Other,

yet unknown, clay-based materials are likely to emerge, given the inventiveness

of man. Thus, the scope of clay science is very wide, if not unlimited.

(iv) Development of new layered mate rials, such as LDH (see Chapter 13.1), alkali

silicates, crystalline sil icic acids, M(IV)-phosphates, niobates, titanates, etc.

(Lagaly and Beneke, 1991; Schwieger and Lagaly, 2004).

(v) Interdisciplinary approach and collaboration. Although not new, this concept is

gaining ground and acceptance. For example, the biological sciences become an

important part of clay research (Theng and Orchard, 1995) (see also Chapter 9).

15.2. NAMES, FIRST LOCALITY, AND STRUCTURAL IDENTIFICATION

Allophane (Hausmann and Stromeyer, 1816): The name ‘allophane’ was ﬁrst ap-

plied by Hausmann and Stromeyer (1816) to material lininig cavities in marl near

Balingen, Germany. The term derives from Greek allos (differ ent, other) and phane

(appear, appearance), and alludes to the ability of allophane to change from a glassy

material to one with an earthy appearance as water is lost on standing. Since the

work of Hausmann and Stromeyer, a variety of materials were described or classiﬁed

as allophane. Because these materials were generally amorphous, allophane came to

be identiﬁed with the (X-ray) amorphous constituent s of clay (Grim, 1968). Struc-

tural identi ﬁcation: (Ross and Kerr, 1934).

Attapulgite (de Lapparent, 1936): The name ‘attapulgite’ was ﬁrst applied by

Molie

re Jacques de Lapparent (1883–1948) to the clay that he found in fuller’s ea rth

from Attapulgus, Georgia (USA); Quincy, Florida (USA); and Mormoiron (Fran ce)

(de Lapparent, 1936). Although ‘attapulgite’ still appears in the literature, the name

‘palygorskite’ should be used in preference. Structural identiﬁcation: (de Lapparent,

1938; Bradley, 1940).

Batavite (Weinschenk, 1897): Ernst Weinschenk (1897) was the ﬁrst to use

‘batavite’ for colourless nacrite-like crystals. The name derives from Castra Batava,

the locality near Passau, Germany. The structure of this mineral is very similar to

vermiculite. Structural identiﬁcation: (Weiss and Hofmann, 1951).

Beidellite (Larson and Wherry, 1917, 1925; Ross and Shannon, 1925): ‘Beidellite’

was ﬁrst used by Larson and Wherry (1925) for a clay mineral found in a gouge clay

in a mine at Beidell, Colorado, USA. The mineral was initially (in 1917) referred to

as leverrierite but Larson and Wherry (1925) later suggested that it was a distinct

Chapter 15: History of Clay Science: A Young Discipline1168

species. The name ‘leverrierite’, after Le Verrier (a mining engineer), was ﬁrst used by

Termier (1890) for a material occurring in black carbonaceous shale near St. Etienne,

France (Grim, 1968). Excellent specimens of beidellite (often showing a weak pink

colour) were found in phonolite quarries near Unterrupsroth, Germany (Heide ,

1928). Structural identiﬁcation: (Ross and Hendricks, 1945; Nadeau et al., 1985).

Bentonite (Knight, 1897, 1898): This clay material was initially called ‘taylorite’ in

honour of William Taylor who ﬁrst drew attention to the correspondin g deposits in

the USA. The name ‘bentoni te’ was given by Knight (1898) after the site near Fort

Benton, Montana, USA where the deposit was ﬁrst discovered. Hewett (1917)

showed that this clay was formed by in-situ alteration of volcanic ash. Structural

identiﬁcation: (Hofmann et al., 1933).

Brammallite (Bannister, 1943; also structural identiﬁcation): Named after

A. Brammall, a British geologist and mineralogist.

Celadonite (Glocker, 18 47 ): Named after the grey-green dress of the shepherd

ladon in the novel L

Astre

e by H. D

Urfe

(1568–1625). Celadonite is a soft grey-

green hydrous silicate of iron, magnesium, and potassium (Glocker, 1847). Similar

materials were earlier referred to as terra verti by de Lish (1783) and Gru

nerde by

Hofmann (1788). Hendricks and Ross (1941) showed that celadonite and glauconite

were similar in structure. The original celadoni te came from amygdalo idal ﬁllings.

Kerr and Hamilton (1948) suggested that the name ‘celadonite’ be retained because it

had a different origin from that of glauconite (Grim, 1968). Struct ural identiﬁcation:

(Hendricks and Ross, 1941).

Chlorites (Werner, 1789a): Abraham Gottlob Werner (1749–1817) was apparently

the ﬁrst to use the name ‘chlorite’ (Werner, 1789a) for a group of green hydrous

silicates, closely related to the micas, and contain ing much ferrous iron. A large

variety of materials were described as chlori tes, and there was much confusion re-

garding the identi ty and validity of species belonging to the group (Grim, 1968).

Structural identiﬁcation: ( Pauling, 1930b).

Corrensite (Lippmann, 1954): The mineral was named in honour of Carl Wilhelm

Correns (1893–1980) (Lippmann, 1960). Structural identiﬁcation: (Stephen and

MacEwan, 1950).

Dickite (Dick, 1908): Allan Brugh Dick (1833–1926), a Scottish metallurgical

chemist, described a mineral from the island of Anglesey, Wales, UK. He did not give a

speciﬁc name, referring to it as a ‘mineral of kaolin’ (Dick, 1908). Ross and Kerr

(1931a) showed that the ‘Dick mineral’ was a distinct species, and were the ﬁrst to use

the name ‘dickite’ (Grim, 1968). Structural identiﬁcation: (Ross and Kerr, 1930, 1931a).

Fuller’s earth (before 3000 BC in Mesopotamia, Egypt and Greec e (Beneke and

Lagaly, 2002b)): The word ‘fuller’ (French foulon; Italian fullone) derives from the

Latin fullo, denoting a person whose job was that of degreasing and felting cloth. In

Roman times, pieces of cloth were ﬁrst steeped into old urine (very rich in ammonia)

or other alkaline solutions, then heavily trod on in a trough or basin containing a

slurry of ‘fuller’s earth’ (Latin creta fullonia). Fresh water was used to rinse off the

15.2. Names, First Locality, and Structural Identiﬁcation 1169

fuller’s earth, and remove a large part of the grease and dirt from the ﬂeece

(Robertson, 1986). This method was also used by the Greeks and Egyptians.

Glauconite (Keferstein, 1827): From Greek glaukos (bluish shining). Structural

identiﬁcation: (Gruner, 1935a; Kohler and Ko

ster, 1976).

Halloysite (Berthier, 1826): The name ‘halloysite’ was given by Pierre Berthier

(1782–1861) to a material found in pockets of carboniferous limestone in a district of

old zinc and iron mines near Lie

ge, Belgium (Berthier, 1826). It was named in

honour of Omalius d

Halloy, a Belgian geologist (1707–1789) who had observed the

mineral several years previously. Prior to the development of X-ray-diffractometry

many materials were descri bed as halloysite. Thus, under halloysite James Dwight

Dana (1813–1895) listed 16 names of minerals that he considered to be synonymous

with it (Dana, 1914). Ross and Kerr (1934) studied a number of halloysites by

modern methods, obtaining samples from the mineralogical collection of the Uni-

versity of Lie

ge. These were probably as nearly representative of the type material

available at the time. They showed that halloysite was crystalline and closely related

to, but distinct from, kaolinite (Grim, 1968). Structural identiﬁcation: (Hofmann

et al., 1934; Mehmel, 1935).

Hectorite (Strese and Hofmann, 1941): The name ‘hectorite’ was given to a ma-

terial from Hector, San Bernadino, California, USA. Structural identiﬁcation:

(Strese and Hofmann, 1941).

Illite (Grim et al., 1937): The term ‘illite’ was proposed by Grim et al. (1937) as a

general term for the ‘‘mica occurring in argillaceous sediments’’. The name derives

from the abbreviation (IL) for the state of Illinois, USA. Prior to 1937 the wide -

spread occurrence of a mica-like, potash-bearing clay mineral, similar to ‘sericite’

and Glimmerton, had been suggested. Grim et al. (1937) voiced objections to these

earlier names, and the term illite was now widely accepted for a mica-type clay

mineral with a 1.0 nm c-axis spacing that shows essentially no interlayer expansion

(in water). Hofmann et al. (1943) suggested ‘sarospatite’ as a substitute for illite.

However, the same objection can be raised, namely, that the type mate rial from

rospatak, Hungary, is a mixture of clay materials. It seems advisable to use a new

name for this group of clay minerals, rather than redeﬁne an old name, parti cularly if

the old name originally describes a mixture of minerals (Grim, 1968). Structural

identiﬁcation: (Grim, 1939).

The name ‘sarospatite’ was initially used by Maegdefrau (1941), and the mineral

was ﬁrst described by Maegdefrau and Hofmann (1937) ( Viczia

n, 2000, 2002).

Imogolite (Yoshinaga and Aomine, 1962a): The name ‘imogolite’ was ﬁrst used by

Yoshinaga and Aomine (1962a, 1962b) for a component present in the clay fraction

of the ‘‘imogo’’ soil, derived from glassy volcanic ash, near Hitoyoshi, Komamoto

Prefecture, Japan. Structural identiﬁcation: (Wada and Yoshinaga, 1969).

Kaolinite (Johnson and Blake, 1867): The name ‘kaolin’ is a corruption of the

Chinese kauling (high ridge), referring to a hill near Jauchau Fu, China, where

the material was obtained centuries ago. Occurrences of kaolinite in many parts of

the world were well documented (see Chapter 10.1). Johnson and Blake (1867) were

Chapter 15: History of Clay Science: A Young Discipline1170

apparently the ﬁrst to use the name kaolinite for the ‘mineral of kaolin’. Ross and

Kerr (1931a) showed that the ka olin minerals were not composed of a single mineral

species. Rather, there are three distinct species of kaolin: kaolinite, nacrite, and

dickite (Grim, 1968). Structural identiﬁcation: (Ross and Kerr, 1931a).

Montmorillonite (Cronstedt, 1758; Damou r and Salvetat, 1847): Mauduyt (1847)

named ‘montmorillonniste’ after the town of Montmorillon, France. Likewise,

Damour and Salvetat (1847) proposed this name for a mineral from Montmorillon.

Correns (1950) suggested ‘montmorin’ as the group name. One year later, the term

‘montmorillonoid’ was suggested as a group name so as to avoid confusion with

montmorillonite as a speciﬁc mineral name (see MacEwan, 1961). Neither of these

names found favour. ‘Smectite’ as a group name was propo sed by the Clay Minerals

Group of the Mineralogical Society of Great Britain. From the outset this proposal

met strong opposition, particularly from many American mineralogists, but it is

becoming widely accepted (Grim, 1968). Structural identiﬁcation: (Hofmann et al.,

1933).

Morencite (Lindgren and Hillebrand, 1904): Morencite from Morenci, Arizona,

USA was ﬁrst described by Lindgren and Hillebrand (1904) as a brownish-yellow

hydrous silicate of ferric iron with magnesium, calcium, and aluminium. Gruner

(1935b) showed the mineral to be structurally the same as nontronite (Grim, 1968).

Structural identiﬁcation: ( Gruner, 1935b).

Nacrite (Brongniart, 1807): From French nacre (mother-of-pearl). The name

‘nacrite’ was proposed by Brongniart in 1807. Later Des Cloizeaux (1862), and much

later Dick (1908), described a nacrite from mines (Einigkeit Mine, Brand-Erbisdorf,

Freiberg) in Saxony, Germany. Dick also provided sufﬁcient analytical data to dif-

ferentiate it from the ‘Dick material’ but not from the ‘mineral of kaolin’. Mellor

(1916) accepted nacrite as a distinct mineral, and Ross and Kerr (1931a) ﬁnally

established its identity (Grim, 1968). Structural identiﬁcation: (Ross and Kerr,

1931a).

Nontronite (Berthier, 1827): Berthier proposed the name ‘nontronite’ for a ma-

terial associated with manganese ore in the arrondissement of Nontron near the

village of Saint Pardoux, France. Chemical analysis showed the mineral to be a

hydrous ferric iron silicate (Berthier, 1827). Collins (1877) appeared to have been the

ﬁrst to recognise the association between nontronite and montmorillonite. The sim-

ilarity of nontronite to montm orillonite was established by Larson and Steiger

(1928), Ross and Kerr (1931b), and Gruner (1935b). Nontronite is now generally

applied to the iron-rich end-member of the montmorillonite group of minerals

(Grim, 1968). Structural identiﬁcation: (Nagelschmidt, 1938).

Palygorskite (Ssaftschenkow, 1862): ‘Palygorskite’ is named after the town of

Palygorsk in the Ural Mou ntains, Russia. Palygorskite and attapulgite are minera-

logically indistinguishable but the name ‘palygorskite’ has priority. Structural iden-

tiﬁcation: (Bradley, 1940).

Pyrophyllite (Hermann, 1829): From Greek py

r (ﬁre), phy

llon (leaf), and lithos

(stone). Structural identiﬁcation: (Ross and Hendricks, 1945).

15.2. Names, First Locality, and Structural Identiﬁcation 1171

Saponite (Sv anberg, 1840): The earliest use of the name ‘saponite’ is difﬁcult to

establish. Svanberg (1840) used this name, derived from Latin sapo (soap). Chemical

analysis showed the material to be essentially a hydrous magnesium silicate. Like

many other clay minerals, this mineral could not be well characterised prior to the

development of modern analytical techniques, and a wide variety of materials were

included under this name. Ross and Kerr (1931b) identiﬁed saponite as a member of

the montmorillonite group with a high content of MgO. Ross and Hendricks (1945)

deﬁned saponite as a member of the montmorillonite group for which the replace-

ment of Al

by Mg

in the octahedral sheet was essentially complete, while some

replacement of Si

by Al

occurred in tetrahedral positions (Grim, 1968). Struc-

tural identi ﬁcation: (Ross and Hendricks, 1945).

Sauconite (Roepper, 1875): Sauconite is named after the locality: Ueberroth mine,

Saucon Valley, near Friedensville, Lehigh County, Pennsylvania, USA. (Roepper,

1875). Structural identiﬁcation: (Ross, 1946).

Sepiolite (Glocker, 1847): The name ‘sepiolite’ is derived from Greek sepion

(squid, cuttleﬁsh) and lithos (stone). First locality : Baldissero Canavese, Piemont,

Italy. ‘Sepiolite’ and ‘Meerschaum’ were long considered as synonymous. Werner

(1789b) was apparently the ﬁrst to use the name Meerschaum (German, meaning sea

froth) in allusion to the lightness and colour of the material. The term ‘sepiolite’ was

ﬁrst used in 1847 by Ernst Friedrich Glocker (1793–1858) because the mineral was

light and porou s like the bone of cuttleﬁsh. Structural identiﬁcation: (Migeon, 1936;

Nagy and Bradley, 1955).

Smectite: ‘Smectite’ is a group name, derived from Greek smectis (fuller’s earth)

and smechein (wipe off, clean) (see montmorillonite).

Stevensite (Leeds, 1873): Named after E.A. Stevens, founder of the Stevens In-

stitute of Technology, Hoboken, New Jersey, USA. First locality: the railway tunnel

at Bergen Hill, Hudson Coun ty, New Jersey, USA. Structural identiﬁcation: (Faust

and Murata, 1953).

Vermiculite (Webb, 1824): The name ‘vermiculite’ derives from Latin vermiculari

(full of worms). It was ﬁrst used by Webb (1824) for a platy mineral from Millbury

near Worchester, Massachussetts, USA as the (hydrated) mineral exfoliates when

heated and wriggles like a worm (see Chapters 7.2 and 10.1). Structural identiﬁca-

tion: (Gruner, 1934, 1939).

Volkonskoite (Anonymou s, 1830): This mineral was discovered on a certain estate in

the Province of Perm (Perm Basin, Ural Mountains, Russia) and named in honour of

the Minister of the Imperial Court, Prince Volkonskoi (Anonymous, 1830; Mackenzie,

1984). Structural identiﬁcation: (Ross and Hendricks, 1945; Weiss et al., 1954).

15.3. HISTORY OF CLAY MEETINGS

In 1948 the ﬁrst international clay committee under the presidency of Ralph Grim

decided to promote cooperation between clay scientists from diff erent countries. To

Chapter 15: History of Clay Science: A Young Discipline1172