Tanya

An important source of precious material is secondary sediments such as sand and gravel. They contain not only minerals deposited as a result of erosion of primary erupted rocks, but also minerals such as sapphire, ruby, spinel, brought from metamorphic rocks. The alluvium is used to mine a significant amount of diamonds, but in addition to this precious mineral, productive gravel probably accounts for about half of the total gemstone production. Sand and gravel are varieties of sedimentary rocks...

Beauty is one of the three main advantages of perfect gemstone. It is the beauty that is noticed first, and, of course, it can be considered as the main of the three qualities, because beauty, due to the color or transparency of the stone or a combination of these properties, attracts the human eye to the stone. These qualities are closely related to the structure of the stone; therefore, gemstones (except for opal and turquoise, which are valued as ornamental stones) are the most beautiful examples of crystals that nature is capable of...

Subtype 1-1. Transparent stones: Group I - 1 – 1. Hardness 10 — diamond; Group I -1-2. Hardness 7-10 — corundum, beryllium, tourmaline, Garnet, chrysoberyl, spinel, Quartz monocrystals, Topaz, Euclase, phenacite, zircon, cordierite, Andalusite, staurolite; Group I-1-З...

Collection stones are samples of minerals and mineral aggregates of scientific and educational interest, as well as of decorative and artistic value. Educational collection material is used as visual aids in teaching at schools, technical schools and universities. It includes representative samples of various minerals, rocks, and ores. These samples should be visual and typical, with well-defined diagnostic features. Another type of collector's stone is intended for scientific research, as well...

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),...