British Museum Materials Thesaurus


Editor's preface
Structure and content of the thesaurus
Sources consulted
Alphabetical list with links:
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
Index of terms:
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
Note on This Version

Editor's preface

The decision to publish The British Museum materials thesaurus was based on the interest shown in it over the years by visiting documentation specialists, and their requests for copies. In my opinion, the thesaurus is unique, due to the great range of terms included, the inevitable consequence of documenting world-wide collections from almost any historical period, a great variety of cultures, and covering almost any type of object. The eclectic nature of the listing precluded the possibility of importing a thesaurus into our documentation system, and we therefore had to devise our own version. The greatest difficulty lay in providing an overall structure which could accommodate specialised terminology, archaic or local names for certain materials, and everyday nomenclature as well. Our thesaurus indicates one approach, no doubt there are many others (indeed we tried several before settling on the current structure). I am reassured by the fact that our users regularly retrieve records by material, using the thesaurus as a retrieval tool.

I would be very grateful to receive comments and suggestions, but stress that we did not attempt to cover all materials from which objects can be made, and that we intended to produce a pragmatic, rather than a scientific, thesaurus. It is strictly based on The British Museum's documentation of its collections, and will be regularly updated as new terms are added at data entry, or as a result of research by curatorial, scientific or conservation staff.

Tanya Szrajber
Department of Scientific Research
The British Museum
August 1997

[Top of page ]


A thesaurus is a hierarchical list of terms, which may be inter-related and often have explanatory notes called Scope Notes. Thesauri are used to standardise terminology, thereby achieving consistency in data entry and facilitating retrieval. The British Museum's collections documentation project has established several thesauri, and the following abbreviations define the status and relationships of the terms.

PT: Preferred Term - a term is a PT by default, and the user is recommended to use it.

NP: Non-Preferred Term - the user is advised not to enter the term, but to use the associated PT instead.

BT: Broad Term - a term encompassing one or several terms beneath it in the hierarchy.

NT: Narrow Term - a term placed under a higher level term in the hierarchy.

RT: Related Term - a term comparable to other terms in the thesaurus, which may be a useful alternative for retrieval.

TT: Top Term - a term at the highest possible level in the hierarchy, provided primarily for classificatory purposes; such a term should rarely be used in data entry.

TE: Temporary Term - a term awaiting discussion by the Working Party for possible incorporation into the thesaurus.

Scope Note - an explanatory note accompanying a term.

The Materials thesaurus was initially compiled from index terms generated from computer records created using curatorial documentation and the objects themselves. A Working Party was set up with representatives from the Collections Data Management Section (CDMS) associated with various curatorial departments. Terms were vetted, incorporated into an overall hierarchical structure, and other thesaural relationships and features added. Curatorial and Conservation staff were consulted over problematic or ambiguous entries, and the final lists were checked by colleagues in the Department of Scientific Research. It is stressed that the final listing is not intended as a scientific classification system, rather it is a reflection of the terminology, both current and historical, in use in curatorial departments in The British Museum. As with all British Museum thesauri, Temporary Terms can be set up at data entry, to be discussed by the Working Party and if suitable, added to the thesaurus. Scope Notes are provided to explain the meaning of the more obscure entries or to restrict usage to a particular context or department. The terms are in the singular form, and hyphens are avoided, unless they reflect standard spelling. Foreign words are included, although higher-level terms are in English.

[Top of page ]

Structure and content of the thesaurus

Three Top Terms are provided - 'Organic', 'Inorganic' and 'Processed Material' and are generally mutually exclusive. 'Organic' is defined as naturally occurring animal and plant material, and naturally occurring substances derived from them. 'Inorganic' is defined as naturally occurring material which, for the purposes of this thesaurus, is not of organic origin, i.e. mainly minerals and stones. 'Processed material' may be regarded as material which has been manufactured or has undergone some form of processing (such as smelting) to alter it from its original natural state. The definitions of the three categories are provided for general guidance, rather than as strict formulations. It is accepted that there are grey areas, particularly in deciding whether a substance is processed or not. However the primary intention is to group materials in a way which is meaningful to the average user.

The following structure shows the main categories.

ORGANIC: animal
INORGANIC: aggregate
silver chloride
silver nitrate
white paste

It was decided that for the sake of simplicity, materials in the 'Processed Material' category would not be placed under more than one Top Term. The only exceptions occur for certain textile terms which refer to the cloth and the primary material, such as 'cotton'.

A category 'Unknown' has also been created to cover instances where the material is genuinely unidentified and requires analysis. The Material field should be left blank if the material has been omitted from the documentation.

The Materials thesaurus should be used in conjunction with the Object Names thesaurus for certain terms which might conceivably fall under either category, For example terms such as 'dye' or 'paint' are regarded as Object Names (under the Broad Term 'sample') and their constituents (such as 'urucu') as materials.


The main categories are animal and vegetal materials which have been arranged primarily by constituents such as 'bone' or 'wood', reflecting the most common types of retrieval requests. As shown in the accompanying diagrams (Fig. 1 and Fig. 2) these are then subdivided into named examples, such as 'mammal bone' or 'pear wood'. There is no attempt to provide taxonomic classifications of animals and plants, although some form of grouping does occur.

The thesaurus allows for two types of search. The user can retrieve records relating to a particular animal or plant by searches for terms beginning with the specific name (e.g. 'tiger' or 'areca palm'). Alternatively, the user can retrieve according to constituent by making use of the Broad Terms (e.g. 'seed' or 'claw') regardless of the particular animal or plant.

The 'animal' and 'vegetal' sections also incorporate terms for materials extracted from plants or produced by animals, under the Broad Terms 'plant extract' or 'animal product'.

The 'Organic' category also includes the hydrocarbons (e.g. asphalt, bitumen, coal, jet, pitch and tar) which are defined in this thesaurus as naturally-occurring although they may in some classification systems be regarded as processed. Other materials of particular interest are the so-called 'organic gem materials' which occur in various sections of the 'Organic' category and include amber, copal, coral, jet, mother-of-pearl, pearl, shell and vegetable ivory.


The first level of Broad Terms is a list of constituents (e.g. 'hoof' or 'bone') including 'animal tissue' which, like its Narrow Terms, does not refer to 'tissue' in a strict biological sense. It is a necessary inclusion for instances in which a combination of constituents (e.g. 'donkey leg'), unspecified matter from a named animal, or even the whole animal name (e.g. 'catfish') have been used in the documentation.

Further down the hierarchy the names of specific animals (e.g. 'parrot feather') or groups (e.g. 'mammal claw') are incorporated. The level of specificity reflects the documentation, which may record 'mammal bone' in some instances, or 'arctic fox bone' in others. For this reason, certain intermediary Broad Terms which might be expected are not included (even though comparable terms are present). Thus, for example, 'marsupial fur', 'marsupial bone', etc. are listed, but 'marsupial claw' is not (and 'kangaroo claw' therefore has BT 'mammal claw'). As stated, the thesaurus does not reflect an attempt to provide a rigorous classification system, but rather to incorporate data used in the British Museum records.

The category 'animal product' comprises materials produced by animals (e.g. 'ambergris' or 'beeswax') as opposed to materials extracted from them (such as 'animal oil' or 'animal fat').


The first level of includes a list of constituents (such as 'seed' or 'fibre'), the specific term 'charcoal', and the two Broad Terms 'plant extract' (with Narrow Terms such as 'indigo' or 'henna') and 'plant specimen'. The latter functions in a similar way to 'tissue' in the animal hierarchy, as it is a Broad Term for named specimens such as 'acacia' (which could refer to unspecified parts or the entire plant), although it can also be entered as a Preferred Term for un-named specimens. Further down the hierarchy, the names of specific plants or groups, are included, as with the animal section (e.g. 'cucumber seed' or 'palm leaf'). No attempt has been made to provide a classification of terms in the 'Vegetal' section, such as 'monocotyledon leaf' or 'hardwood', since such terms have not been used in the records.

In a small number of cases, the constituent is not actually named, but rather is implied. After some deliberation, it was decided that if a term naturally suggested a constituent in everyday language, it was unnecessary to specify it. Thus, for example, it is assumed that 'willow' refers to the wood (and therefore has the Broad Term 'wood') but other references have to be fully specified (e.g. 'willow bark'). The same argument applies to various kinds of fruit or flower. Since 'rose' implies the flower, and 'peach' the fruit, etc., it is unnecessary to specify 'rose flower' or 'peach fruit', which would be clumsy terms in everyday usage.


This category comprises mainly minerals and stones. Minerals are loosely defined as naturally occurring chemical compounds of non-biological origin. Since minerals have a 'chemical' name as well as a 'mineral' name, either of which may have been used in the documentation, both versions will be Preferred, with the 'chemical' name as the Broad Term). As mentioned above, it was decided to place 'organic gem materials' in the Organic section of the thesaurus.

Stones are loosely defined as combinations of minerals. The term 'stone' is also the material which should be entered in the case of fossils, and 'fossil' retained as an Object Name. This category (and the one below) also include 'lime' because it has been used to cover several substances in the documentation, which can only be distinguished through future analysis.


This essentially comprises man-made materials (e.g. 'rayon') and others which have been altered in some way from their natural state (e.g. 'pottery'). It is impossible to define how much or what kind of processing is necessary before a material is placed in this part of the thesaurus, and common sense is the ultimate guide. The presence of some categories may not be immediately obvious to the average user, as in the case of 'metal', which is included because in most cases it has undergone extraction and smelting before being used. The term 'synthetic' is a Broad Term for all plastics, and should also be entered as the material for objects which are described as being made of 'synthetic wool' or 'synthetic caribou sinew', for example, in the absence of a more specific information. An important category in this section is 'textile', which covers any cloth, whether woven, knitted, beaten, or otherwise manufactured. Where the primary material of the textile is definitely established for all cases, the link has been made in the thesaurus by a providing a second Broad Term (e.g. 'calico' has BT: 'cotton' and 'textile'). Where the primary material may vary, the connection has to be made in each individual record by multiple keywords:

e.g. [velvet]

The term 'textile' should also be entered as an additional keyword in instances where materials which are not Narrow Terms of 'textile' have nevertheless been used in this context. An example might be a garment made of woven palm leaf, which would have the following entries in the Materials field:

e.g. [palm leaf]

CDMS (Materials Working Party)
Department of Scientific Research
The British Museum

[Top of page ]

Sources consulted

Allaby, M. (ed.). The Concise Oxford Dictionary of Botany, Oxford, 1992.

Clutton-Brock, J. A. Natural History of Domesticated Mammals, Cambridge University Press and British Museum (Natural History), 1987.

J. Paul Getty Trust. Art & Architecture Thesaurus, Oxford University Press, New York, 1994 edition.

Hodges, H. Artifacts - An introduction to early materials and technology, London, 1964.

Royal Commission on the Historical Monuments of England. Thesaurus of Building Materials, [unpublished], 1996.

Whitten, D. G. A. with Brooks, J. R. V. A Dictionary of Geology, Penguin Books, 1972.

[Top of page ]


Current CDMS Working Party (1995-7): Sandor Burslem, Amanda Gregory.

Chair: Tanya Szrajber.

Previous Working Party members: David Bellamy, Fiona Cameron, Simon Cohn, David Collens, Michael Downing, Siobhan Flynn-Collins, Lucy Glazebrook, Daniel Groves, Lea Jones, Bridget Stensel.

Figures by Sandor Burslem and Amanda Gregory.

With special thanks to:
Dr Sheridan Bowman, Dr Caroline Cartwright, Dr Paul Craddock, Dr Ian Freestone, Ms Sylvia Humphrey, Dr Andrew Middleton, Mr David McCutcheon, Mrs Susan La Niece, Ms Allyson Rae, Ms Yvonne Shashoua, Antony Simpson, James Tullett and departmental curators.

Web version prepared by Gordon McKenna of MDA (now Collections Trust)

Note on This Version

Within this version of the thesaurus the use of an '' indicates an hypertext link to another term

[Top of page ]

© Trustees of The British Museum, 1997.
You may freely download this page for non-profit use, but must acknowledge the Trustees in any output in which it is used.
The Trustees acknowledge the work of MDA (now Collections Trust) in converting this resource for use on the Web.