Gemmology
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Thursday, 21 February 2019


Gemmology — gemstones — characteristics, classification, specimens, library
Hackmanite

GEMMOLOGY — GEMSTONES

characteristics, classification, specimens, library

As gemstones we accept cut specimens of crystals of natural mineral species having a visible transparency and certain durability. From over 4800 known minerals (according to data of the International Mineralogical Association), approximately 150 satisfy the above conditions and form crystals of sufficient size to be cut.

The section ‘Classification’ presents descriptions of 171 different kinds of natural gemstones (106 mineral species). The Nickel-Strunz systematic order (10th edition) is used. Since gemmology does not always follow the systematics of minerals in naming, many popular varieties or just ’names’ are listed.

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Classification
Featured

Actinolite

— Produced by regional or contact metamorphism of magnesium carbonate, mafic, or ultramafic rocks (Anthony et al., 2001—2005). Faceted specimens are extremely rare.
Actinolite

The section ‘Repository’ contains data and photos of 760 specimens of gemstones. The smallest is just 1.96 mm (0.02 ct) ruby from Mozambique, and the largest — 70.11 mm (326.60 ct) rock crystal from Africa. Besides there are 8 specimens of synthetic stones.

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Repository
Morganite — specimen 0482

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Dolomite — specimen 0165
Chrysoberyl — specimen 0166
Opal — specimen 0167
Johachidolite — specimen 0174

— More from ‘Repository

Currently there are 283 bibliographical references and abstracts to publications with gemmological or mineralogical thematics in the ‘Library’. The section comprises also a glossary with 391 terms.
Library
Glossary

heliodor — variety of beryl; see heliodor in ‘Classification’
heliotrope — synonym of bloodstone
hematite — species of mineral; see hematite in ‘Classification’
hemimorphite — species of mineral; see hemimorphite in ‘Classification’
Publications

von Leonhard, K. C., 1821 — Scheelit — Published in 1821 in ‘Handbuch der Oryktognosie’; contains the original description of the mineral scheelite.
Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Uvite — Features the data of uvite; from ‘Handbook of Mineralogy’.