Stones photo gallery

How are gemstones classified?

Illustration from the book by M.G. Bauer “Gemology; a clear understanding of the properties, deposits and uses of gemstones, along with guidance for mineralogists, gemstone lovers, cutters and jewelers”

He divided the minerals that had been discovered by that time into large classes. Precious and semi-precious stones were ranked by value – from expensive to cheaper, from jewelry to semi-precious. A separate group includes precious organic stones – jet (sedimentary coal rock, also known as “black jasper”), pearls, amber and coral.

Alexander Fersman, a Russian and Soviet geochemist and academician of the Russian Academy of Sciences, supplemented and improved the system of his German colleague. He also introduced new concepts: precious stones – “gems”, semi-precious stones – “colored”. Precious gems are transparent, translucent or translucent minerals that seem to emit light and are used in small inlays as the most valuable. Colored stones are opaque and are suitable for small inserts in jewelry, as well as for cladding any surfaces.

The real value of many minerals described in the Bauer-Fersmann system has undergone significant changes. New deposits were discovered, while old ones were completely depleted. All this led to the fact that the system in its original form became unusable.

In 1973, Soviet geologist E.Ya. Kievlenko made adjustments to this classification. Kievlenko also replaced outdated terms in the nomenclature of minerals. For the first time, the classification began to take into account the actual cost of the mineral on the market and its purpose. As a result, natural minerals were divided into three groups:

  • Jewelry (precious) stones (divided into four classes in descending order of value and jewelry properties);
  • Jewelry and ornamental stones (2 classes);
  • Ornamental stones.

This systematization was considered the most convenient and reliable. Over time, this system also became outdated. In 2010, Professor of Geological and Mineralogical Sciences E.P. Melnikov, in turn, reworked Kievlenko’s classification system. The principle of distributing precious stones into classes and orders is based on their value and functionality.

Modern classification of stones and minerals by E. P. Melnikov

Value

A mineral that is characterized by a high degree of hardness and transparency is considered precious. Such minerals can look like new for a long time and do not lose color (if any). At the head of this group are diamonds. Together with them, precious ones include: blue sapphire, emerald, ruby, natural sea pearls and alexandrite.

Jewelry stones of the first order

noble red spinel, padparadscha sapphire, pink sapphire, demantoid, tsavorite, noble black opal, tanzanite, Paraiba tourmaline

Jewelry stones of the second order

sapphire yellow, green, purple; star sapphires and rubies; ganospinel; topaz imperial; aquamarine; sparrow; bixbit; maxis; green and blue hyacinth; polychrome rubellite; noble white and fire opals; phenacite; Malaya; rhodolite; topazolite; ametrine; giddenite; kunzite; natural river pearls; saltwater cultured pearls

Jewelry stones of the third order

verdelite; indigolite; heliodor; goshenite (rosterite); topaz yellow, blue, pink; chrysolite; leucosapphire; chrysoberyl (noble cat’s eye); star diopside, colorless topaz, pyrope; spessartine; almandine; grossular (hessonite, leucogranate, rosolite); uvarovite; amethyst; prasiolite; citrine; rutile quartz

Jewelry stones of the IV order

drags; achroite; tektites (moldavites, australites); quartz and other cat’s eyes, hawk’s eye; Tiger’s Eye; morion; andradite; Vesuvian; axinite; cordierite (iolite), clinohumite; cornerupin; euclase; amblygonitis; brazilianite; scapolite; apatite; chrome diopside (sibirlite); kyanite;andalusite; epidote; sphalerite; marmatite; sphene; cassiterite; scheelitis; danburite; prehnite; freshwater cultured pearls; nacre

Jewelry and ornamental stones of the first order

charoite; sugilite; malachite; turquoise blue, green; jade; lapis lazuli; nephritis; anionite; rhodonite; rhodochrosite; dumortierite; rose quartz; mammoth and ivory; coral; amber; agate; chrysoprase; cornelian; sapphirine; onyx; heliotrope; sodalite; eudialyte; chrysocolla; azurite

Jewelry and ornamental stones of the 2nd order

rhinestone; smoky quartz; amazonite; decorative quartz – tourmaline, chlorite, actinolite; aventurine; hematite; rhodusite; staurolite; astrophyllite; finely patterned and landscape jasper; simbircite; common opal; iridescent obsidian; iridescent feldspars – labradorite, spectrolite, belomorite; sun stone; moonstone (adularia); Eleolithic; jade; larimar; tugtupit; petalite; quartz – granular, icy, fragmentary

Ornamental stones

Jasper is plain, banded; written granite; petrified wood; cacholong; marble onyx; obsidian; selenite; clinochlor; fluorite; serpentinite; jet; shungite; thulite; patterned skarn; decorative quartzites; ophiocalcite; agalmatolite; soapstone; goldite; patterned flint; conglomerate; breccia; decorative porphyry

Classification by mineral groups

Types of minerals that are similar in chemical composition form groups. For example, aluminum oxides are corundum, beryllium and aluminum silicate are beryl.

Group of pomegranates

The garnet group is a broad type of mineral that belongs to the silicate class. They have a characteristic glassy luster and an average hardness of 6,5 – 7,5 on the Mohs scale. The most famous representatives of the group are garnet, rhodolite, grossular, andradite, pyrope.

Quartz group

Quartz is silicon dioxide. It is the most common mineral in the earth’s crust – 12%. The luster of quartz is often glassy; sometimes there are arrays with a greasy luster. Quartz is a large group of relatively hard minerals – Mohs 7 on average. Rock crystal is a transparent variety of quartz, all kinds of “eyes” – cat, tiger, falcon, etc. This also includes jewelry amethysts and jewelry and ornamental jasper.

Feldspar group

Feldspars are silicon silicates that make up up to 50% of the mass of the earth’s crust. When feldspars break down, sedimentary rocks and clay are formed. Feldspars can often be found combined with quartz crystals. Feldspars include adularia, labradorite, oligoclase and other minerals.

Group of Jades

Jades are a group of translucent jadeites and jades. The value of jads increases as you move to the southeast. In China, this mineral is presented as an expensive gift to dear people. The most common color of these stones is green, but white, yellow and lavender are also found. Jades include jadeite, jade, obsidian and other minerals.

Group of organic materials

Organic materials are formed by living things and are composed entirely of organic compounds. The properties of minerals in this group are quite diverse and depend on their origin. This group of materials includes coral, pearls, amber, shungite and others.

Value – minerals with properties that allow these stones to be used for the manufacture of jewelry, decorations and decorative arts. Among the properties that determine dignity gemstone refers to the beauty of the stone, coloring, different colors and shades, shine of precious stones, transparency, play of light and hardness of the stone, which determines its durability, ability to maintain shape without change and properties under mechanical stress. No less important is its rarity – the rarer it is, the higher its value.

Precious jewelry stones classified according to a number of specific characteristics. Minerals are divided:
– by origin (genetic classifications), by their composition, by the element most characteristic of them (for example, minerals containing iron, tin, copper, etc. are distinguished),
– according to crystallographic characteristics.

Currently, the most common classification of minerals is by chemical composition (by types of chemical compounds and bonds), taking into account their structural types.

  • 1) precious;
  • 2) medicinal;
  • 3) stones used in construction, for making vases, statues, etc.

In 1860, the German scientist K. Kluge (1860) proposed practically the first scientifically based classification of precious and semi-precious stones, which he divided into two groups: truly precious minerals and standard precious minerals. The first group included stones of classes I, II and III, and the second – class IV and V.

K. Kluge classified diamond, corundum, chrysoberyl and spinel into class I, zircon, beryl, topaz, tourmaline, garnet, noble opal into class II, cordierite, vesuvian, chrysolite, axinite, kyanite, staurolite, andalusite into class III, chiastolite, epidote and turquoise.

In the group of semi-precious stones, K. Kluge included class IV stones: quartz (amethyst, rock crystal, rose quartz, aventurine), chalcedony (agate, carnelian, plasma, heliotrope, cacholong, jasper and ordinary hydrophane), feldspars (adularia, amazonite, Labradorite), obsidian, lapis lazuli, hauin, hypersthene, diopside, fluorite, amber and V class: jadeite, jade, serpentine, agalmatolite, bronzite, satin spar, marble, selenite, alabaster, malachite, pyrite, rhodochrosite, hematite, prehnite, nepheline , lepidolite, etc.

The classification of precious stones by the German professor of mineralogy G. Gurich (1902) is very close to the classification of K. Kluge. He combined all transparent minerals, characterized by high light refraction and used for making jewelry, into precious stones of the first kind; semi-precious stones were identified separately. Minerals that occur in an amorphous state or in the form of fine-grained crystalline aggregates are classified as a group of stones of the second type (colored stones). According to their value, G. Gurich divided precious stones into five different classes. Precious stones of class I – diamond, corundum, chrysoberyl and spinel, class II – zircon, beryl, topaz, tourmaline and garnet, as well as noble opal from the group of colored stones, class III – cordierite, peridot, kyanite and other precious stones, in addition turquoise from the group of colored stones. Class IV included semi-precious stones such as quartz, feldspar, fluorite and from the group of colored stones – aventurine, cat’s eye, chalcedony, opal, obsidian, lapis lazuli and amber. Class V includes colored stones from the group of colored ones: hematite, nepheline, jade, jet, serpentine, alabaster, malachite, etc. At the end of the 1896th century. M. Bauer (XNUMX) proposed a new classification of precious stones, which for a long time was popular among mineralogists and jewelry specialists. M. Bauer’s classification was later supplemented and expanded by A.E. Fersman. Jewelry and ornamental stones are divided into three groups: I – precious stones (gems), II – ornamental stones (colored stones), III – organogenic precious stones. Within the group, depending on their value, stones were divided into orders. Group I included mainly transparent, colorless or beautifully colored precious stones and some translucent colored stones used in faceted form. Group II includes a number of minerals and rocks suitable for cabochoning and various crafts. Below is the classification of M. Bauer – A.E. Fersman. Groups of stones:

I. Precious stones (gems):

1st order: Diamond, ruby, sapphire, emerald, alexandrite, noble spinel, euclase.

2nd order: Topaz, aquamarine, beryl, red tourmaline, demantoid, blood amethyst, almandine, uvarovite, jadeite, noble opal, zircon.

3rd order:
1. Garnet, cordierite, kyanite, epidote, dioptase, turquoise, variscite, green tourmaline;
2. Rock crystal, smoky quartz, light amethyst, chalcedony, agate, carnelian, heliotrope, chrysoprase, praseme, semi-opal;
3. Sunstone, moonstone, Labradorite, nepheline, sodalite, obsidian, titanite, benitoite, prehnite, andalusite, diopside, scapolite, thomsonite;
4. Hematite, pyrite, cassiterite, quartz with gold;

II. Ornamental (colored stones):

1st order: Jade, lapis lazuli, glaucolite, sodalite, amazonite, Labradorite, rhodonite, azurite, malachite, aventurine, quartzite, rock crystal, smoky quartz, agate and its varieties, jasper, vesuvian, rose quartz, written granite.

2nd order: Lepidolite, fuchsite slate, serpentine, agalmatolite, steatite, selenite, obsidian, marble onyx, datolite, fluorite, halite, graphite, lapis lazuli, smithsonite, zoisite.

3rd order: Gypsum, porphyry and partially decorative material – breccias, confluent quartzites, etc.

I II. Precious stones – organogenic: Pearls, coral, amber, jet.

The above classification was used for a long time in the USSR and abroad. However, it is not without a number of disadvantages. Thus, some minerals are simultaneously classified into different orders (rock crystal, agate, smoky quartz, lapis lazuli, etc.); in some cases, group mineralogical names are given simultaneously with specific, private names (garnet and almandine with uvarovite, beryl and aquamarine, chalcedony and agate, carnelian, chrysoprase, etc.). The group of ornamental stones includes a number of minerals that currently have a relatively high value, are considered semi-precious and are widely used in jewelry (aventurine, malachite, amazonite, rock crystal, smoky quartz, rose quartz, lapis lazuli, etc.). Currently, the practical value of many precious stones has changed significantly, and therefore the Bauer-Fersmann classification is outdated. In recent years, refined and simplified versions of the Bauer-Fersman classification have been proposed. Below is the classification proposed by V.I. Sobolevsky.

1. Precious stones (gems)

Class I: diamond, emerald, alexandrite, chrysoberyl, euclase, noble schlinel and especially rare varieties of corundum: ruby, sapphire, padparadscha (orange sapphire).

Class II: topaz, varieties of beryl (aquamarine, sparrowite, heliodor), pink and dark red tourmaline (siberite), phenacite, amethyst, zircon (orange hyacinth, green, etc.), noble opal.

III class: turquoise, rock crystal (colorless and smoky rauchtopaz), chrysoprase, carnelian, agates with beautiful designs, bloodstone, amber, jet, etc.

2. Colored stones

Class I: malachite, rhodonite, jade, lapis lazuli, amazonite, labradorite, aventurine, chalcedony, written granite, etc.

Class II: ophiocalcite, agalmatolite, marble onyx, fluorite, selenite, jasper, meerschaum, etc.

In 1973 E.Ya. Kievlenko proposed a modernized classification of colored stones, which takes into account their market value and applicability in jewelry and stone-cutting items. Kievlenko distinguishes three groups of stones: jewelry (precious), jewelry and ornamental and ornamental.

I order: diamond, emerald, blue sapphire, ruby.

II order: alexandrite, noble jadeite, orange, yellow, purple and green sapphire, noble black opal.

III order: demantoid, noble spinel, noble white and fire opal, aquamarine, topaz, rhodolite, moonstone (adularia), red tourmaline.

IV order: blue, green, pink and polychrome tourmaline, noble spodumene (kunzite, giddenite), zircon, yellow, green, golden and pink beryl, turquoise, peridot, amethyst, chrysoprase, pyrope, almandine, citrine.

The second group:

I order: rauchtopaz, hematite-bloodstone, amber-su-cinite, rock crystal, jadeite, jade, lapis lazuli, malachite, aventurine.

II order: agate, colored chalcedony, cacholong, amazonite; rhodonite, heliotrope, rose quartz, iridescent obsidian, common opal, Labradorite, belomorite and other opaque iridescent spars.

Third group: Jasper, written granite, petrified wood, marble onyx, listvenite, obsidian, jet, jaspilite, selenite, fluorite, aventurine quartzite, agalmatolite, patterned flint, colored marble.

In addition to the above, classifications of precious stones by Sinkancas (1955), R. Webster (1962), Pearl (1965) and a number of other researchers are known abroad. Each classification is characterized by its own characteristics and differences. According to the authors, in addition to the basic principles underlying the classifications, there are a number of external factors – established traditions, fashion for stones, the availability of precious stones on the market, the discovery of new deposits of precious stones, etc. Therefore, individual stones in different classifications may occupy one place or another, although the general nature of the classifications is basically the same.

With the development of the jewelry and stone-cutting industry in the USSR in 1970-1980. It became necessary to create an industrial classification of jewelry and semi-precious stones suitable for the practical work of this new industry. The All-Union Scientific Research Institute of the Jewelry Industry (VNIIyuvelirprom) developed such a classification. In it, all jewelry and semi-precious stones are divided into three types: jewelry, jewelry-ornamental and ornamental, which, in turn, are divided into subtypes and groups based on transparency, hardness (on the Mohs scale) and other properties. Below is the industrial classification of natural jewelry and ornamental stones, developed by VNIIyuvelirprom.

Type I. Jewelry stones

Subtype 1 – 1. Transparent stones:

group I – 1 – 1. Hardness 10 – diamond;
group I – 1 – 2. Hardness 7-10 – corundum, beryl, tourmaline, garnet, chrysoberyl, spinel, quartz single crystals, topaz, euclase, phenacite, zircon, cordierite, andalusite, staurolite;
group I – 1 – H. Hardness less than 7 to 5 – spodumene, chrysolite, kyanite, dioptase, brazilianite, tanzanite, chrome diopside, apatite, benitoite, axinite, scapolite, thomsonite, danburite, ulexite, cassiterite, gambergite, actinolite, green obsidian;
group I – 1 – 4. Hardness less than 5 – sphalerite, fluorite, brucite,
zincite, scheelite.

Subtype I – 2. Opaque, sparkling stones:

group I – 2 – 1. Homogeneous – hematite-bloodstone, pyrite, cobaltine, psilomelane;
group I – 2 – 2. Patterned – hematite-goethite glass head, cryptomelane-hollandite glass head.

Subtype I – 3. Translucent stones:

group I – 3 – 1. Brightly colored stones – carnelian, chrysoprase, chloropal, rose quartz, colored semi-opals, smithsonite, prehnite, zoisite, translucent jadeite;
group I – 3 – 2. Stones with patterns or beautiful inclusions – agate, hairy, moss, onyx (sardonyx, carnelian onyx);
group I – 3 – 3. Stones without patterns and colors – chalcedony, semi-opal, cacholong;
group I – 3 – 4. Pseudochroic stones with a certain orientation – noble opal, moonstone, iridescent obsidian.

Subtype 1 – 4. Opaque matte stones with beautiful colors and dense surface texture:

group I – 4 – 1. Stones used in products with subsequent processing – turquoise, variscite, coral;
group I – 4 – 2. Stones used in their natural form – pearls.

Type II. Jewelry and ornamental stones

Subtype II – 1. Viscous stones, hardness more than 6:

group II – 1 – 1. Jade, jadeite and their hard natural imitations, garnet-chlorite rock, xenolite, fibrolite.

Subtype II -2. Stones of medium viscosity, hardness 5-6:

group II – 2 – 1. Brightly colored stones – lapis lazuli, rhodonite, amazonite, jasper, unakite (an aggregate of epidote and potassium feldspar), charoite;
group II – 2 – 2. Patterned stones – petrified wood, graphic pegmatite, patterned flint, jasper, obsidian, heliotrope, perilivt;
group II – 2 – 3. Pseudochroic stones – belomorite, falcon and tiger eye, silver (“iridating”) obsidian, aventurine, mother-of-pearl;
group II – 2 – 4. Stones used in their natural form:
subgroup II – 2 – 4 a. Massive stones – buds of chalcedony, smithsonite, jade;
subgroup II – 2 – 4 b. Crusts and growths – amethyst and quartz brushes, uvarovite crusts, dendrites of manganese minerals, native copper and silver.

Subtype II -3. Small and medium hard stones:

group II – 3 – 2. Cold processed: malachite, azurite, serpentine, anthracite.

Type III. Ornamental stones

Subtype III – I. Hardness more than 5:

group III – 1 – 1. Glassy – obsidians, jaspers, hornfels, microquartzites, ferruginous hornfels;
group III – 1-2. Heterogeneous rocks and mineral aggregates:
subgroup III-1-2 a. Ice quartz, taganay quartzite, amazonite granite;
subgroup III-1-2b. Peridotites, pyroxenites, hedenbergite skarn;
subgroup III -1-2c. Listvenite, jaspilite;
subgroup III -1-2g. Eclogite, garnet gneiss, tourmaline-bearing rocks;
subgroup III -1-2d. Granitoids, nepheline syenites, labradorite, porphyry, etc.

Subtype III – 2. Hardness from 5 to 3:

group III -2 – 1. Translucent – ​​aragonite and calcite onyx, fluorite;
group III -2 – 2. Opaque – marbles, ophiocalcite, anhydrite, serpentine, chlorite-serpentine rock.

Subtype III – 3. Soft, hardness less than 3:

group III – 3 – 1. Translucent – ​​alabaster, selenite, halite;
group III – 3 -2. Opaque – graphite, soapstone, pyrophyllite, brucite, steatite.

The above classification has a number of disadvantages. So, for example, type I – jewelry stones – includes precious stones of high value and ornamental stones of relatively low value (fluorite, hematite, pyrite, apatite, green obsidian, jadeite, cacholong, chalcedony and a number of other stones). One group I -1-2 includes corundum, beryl, spinel and crystalline quartz, andalusite and staurolite, the cost of which also varies.

Some stones (for example, jadeite, obsidian, quartz group minerals, etc.) of the same name are scattered across different groups, which creates additional difficulties.

Nevertheless, this classification can be successfully applied in jewelry practice.

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