Chalcedony to as prase. However, the term prase is also used to describe green quartz, and to a certain extent is a color-descriptor, rather than a rigorously defined mineral variety.) Blue-colored chalcedony is sometimes referred to as "blue chrysoprase" if the color is sufficiently rich, though it derives its color from the presence of copper and is largely unrelated to nickel-bearing chrysoprase. Heliotrope is a green variety of chalcedony, containing red inclusions of iron oxide that resemble drops of blood, giving heliotrope its alternative name of bloodstone. In a similar variety, the spots are yellow instead, known as plasma. Moss agate
Mineral industry of Kazakhstan main minerals greatly exceeds the speed of their growth after exploration. Reserves increase in case of some metals (iron, manganese, gold, zinc) due mainly through re-evaluation and additional exploration of the already discovered fields. However, the existing registered reserves of recently discovered copper and gold fields have low quality and cannot be considered equivalent to the depleted reserves. Mineral industry of Kazakhstan The mineral industry of Kazakhstan is one of the most competitive and fastest growing sectors of the country. Kazakhstan ranks second to Russia among the countries of the CIS in its quantity of mineral production. It is endowed