Gemmology
English | Български
Monday, 10 August 2026


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.
Characteristics

Colour in gemstones
Clarity in gemstones
Cut in gemstones

Treatment in gemstones

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.

Quick navigation selector

List of minerals
Alphabetic list of gemstones
Synthetic stones and simulants
Classification
Featured

Gadolinite-(Y)

— In granite and alkalic granite pegmatites (Anthony et al., 2001—2005). Faceted specimens are extremely rare.
Gadolinite-(Y)
Rutile
Rutile
Hambergite
Hambergite
Jeremejevite
Jeremejevite
Lazulite
Lazulite

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.

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
Peridot — specimen 0592

Some exceptional specimens of gemstones from our ‘Repository’

More specimens of gemstones
Hambergite — specimen 0487
Hyacinth — specimen 0488
Hambergite — specimen 0489
Phenakite — specimen 0490

— 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

turquoise — species of mineral; see turquoise in ‘Classification’
ultramafic rock — igneous and meta-igneous rock with a very low silica content (less than 45%), composed of usually greater than 90% mafic minerals
umbalite — a synonym of rhodolite; mined in Umba Valley, Tanzania
uvite — species of mineral; see uvite in ‘Classification’
Publications

Тихоненкова, Р. П., Казакова, М. Е. [Tikhonenkova, R. P., Kazakova, M. E.], 1961 — Власовит — новый силикат циркония из Ловозерского массива [Vlasovite — a new zirconium silicate from the Lovozero Massif] — Published in 1961 in ‘Doklady Akademii Nauk SSSR’; contains the original description of the mineral vlasovite.
Anthony, J. W., Bideaux, R. A., Bladh, K. W., Nichols, M. C. (Eds), 2001—2005 — Prehnite — Features the data of prehnite; from ‘Handbook of Mineralogy’.


Gemmology — gemstones
Front page | Introduction | Classification | Repository | Library

© 2026 National Museum of Natural History, Sofia (NMNHS)
Use of this website assumes acceptance of our terms of use.

The specimens illustrated in this site do not exist in the collections of the National Museum of Natural History, Sofia.