Gemmology
English | Български
Tuesday, 28 March 2017


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

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 163 different kinds of natural gemstones (104 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.

Quick navigation selector

Classification
Featured

Sinhalite

— A rare accessory mineral formed in boron-rich skarns at the contact of limestones with granite or gneiss (Anthony et al., 2001—2005). Faceted specimens are relatively rare. The largest faceted stone is a 158 carat from Sri Lanka (Arem, 1987: 173).
Sinhalite

The section ‘Repository’ contains data and photos of 713 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 7 specimens of synthetic stones.

Gallery view selector

Colour selector
Simple colour schemeredorangey redreddish orangeorangeorangey yellowyellowgreenish yellowyellowish greenslightly yellowish greengreenvery slightly bluish greenbluish greenvery strongly bluish greengreen-blue or blue-greenvery strongly greenish bluevery slightly greenish bluebluevioletish bluebluish violetvioletbluish purplepurplereddish purplestrongly purplish redslightly purplish redcolourlessgreyblack
Repository
Topaz — specimen 0562

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Cordierite — specimen 0123
Agate — specimen 0124
Ametrine — specimen 0128
Andesine — specimen 0129

— More from ‘Repository

Currently there are 279 bibliographical references and abstracts to publications with gemmological or mineralogical thematics in the ‘Library’. The section comprises also a glossary with 381 terms.
Library
Glossary

hambergite — species of mineral; see hambergite in ‘Classification’
haüyne — species of mineral; see haüyne in ‘Classification’
heart — rare shape in faceting a gemstone
heliodor — variety of beryl; see heliodor in ‘Classification’
Publications

Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Cerussite — Features the data of cerussite; from ‘Handbook of Mineralogy’.
Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Witherite — Features the data of witherite; from ‘Handbook of Mineralogy’.