All kinds of minerals and rocks can serve as a collection material, but few of them are decorative. The main decorative collection material can be divided into four groups with some conditionality:
1) separate crystals;
2) Druze, crystalline and hidden crystal aggregates;
3) minerals in the rock;
4) highly decorative rocks;
5) organic remains.
Collection material represented by separate crystals includes: amethyst (Ural, Ukraine, Chukotka, Transbaikalia), ruby and almandine (Ural, Baltic Shield), apatite (Pribaikalia, Subpolar Ural), beryl, topaz (Ukraine, Ural), quartz - rock crystal, smoky quartz, citrine, morion, wolframite, pyrite and hematite, tourmaline, etc.д. This also applies to gems - aggregates. Druze, crystalline and crystalline aggregates are distinguished by their individual beauty and uniqueness. Especially beautiful are druses of transparent rock crystal, and sometimes amethyst of crystal veins of the Urals and alpine veins of the Caucasus, aragonite of Central Asia, adular of the Circumpolar Urals, pyrite and hematite-bloods of Kazakhstan. Stone lovers are in great demand for various colors and designs of agates of Timan, Caucasus, Crimea, as well as chalcedony, fossilized wood, etc.
At present, small, shiny, brightly colored crystals on rock planes, usually formed by cracks in separate sections or in the zones of crushing - brushes - are becoming very popular among collectors. The size of the crystals formed by the bases ranges from a fraction of millimeters to 2 cm. The best quality brushes are formed in the cavity of cracks, in the clay material. Small, even crystals brushes are used in the form of inserts in jewelry and art stone-cutting products. Especially beautiful are the dark purple amethyst brushes from the south of the Kola Peninsula, the bright green-green chromium-containing garnet - uvarovita from the chromite deposits of the Urals, and the bright green demantoid from Kamchatka.
The latent-crystalline formations, which are the adornment of any collection, except for agates, include rhodonite, jadeite, chrysoprase, amber, etc. Minerals in the breed can be fascinating in decorative and collectible terms. Original museum samples of the Yakut diamonds in kimberlite, rubies, and spinels in metamorphic breeds of the Urals, etc., chrysolite in basalts of Siberia, tourmaline in quartz from the Urals and Transbaikalia, veins of chrysoprase in the silified serpentinite, emerald greens in mica of the Urals, etc. are original. Highly decorative rocks with bright colors and original patterns are relatively rare. As a rule, among the large massif of homogeneous rocks of high decorative value are only their areas or strips, the formation of which was due to specific conditions of crystallization or change of intrusive rocks, sedimentation and metamorphism - sedimentary rocks.
The group under consideration includes an amazingly beautiful lilac rock - charoite from Eastern Siberia (Chara River), greenish-brown, often striped datolite-vollastonite scarn of Primorye (Tetyukhinskoe), jasper of the Southern Urals, obsidian of the Caucasus, Kazakhstan, marbles of Transbaikalia and Central Asia, etc. Collecting is a large and complex area of consumption of beautiful samples of minerals and rocks — collection material. In recent years, the domestic and foreign literature has published works on colored stones, often well illustrated; collection samples and stone-cutting products produced by the domestic stone-cutting industry have been put on sale; the production of tools for stone processing by collectors has begun; exhibitions of colored stones are held by museums and stone lovers. All this contributes to increasing the interest of the public in stone gems and increasing the demand for collectible material.
Crystallographic collections are collected, in which minerals are represented by separate crystals, their aggregates; mineralogical, systematic. Only one group of minerals (e.g. agates); only minerals from one deposit (such collections can often be seen by miners and geologists in mines) and beautiful stones without any system, the so-called aesthetic collection is the most typical for stone lovers.