Powellite

Powellite is better known as an ore mineral of molybdenum, characteristic of the oxidation zones of sulfide molybdenum deposits. However, with the development of the hydrothermal process, powellite can form crystals and druses, sometimes having a faceting quality. Powellite's hardness ranges from 3.5-4 on the Mohs scale, however, due to its high refractive index and sometimes bright golden yellow color, sometimes described as neon yellow, cuts made from this stone are in demand among collectors. Powellite cuts up to one carat are common, cuts up to two carats are less common, and standard round cuts over two carats are truly rare. Cuts of other shapes can reach more than 5 carats, subject to the visual purity of the stone. Defective stones may also be somewhat larger. Also, bright crystals and druze of powellite are popular among mineral collectors.

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В геммологической практике бывают весьма увлекательные случаи с диагностикой ювелирных вставок

Но помимо редкости цвета и высокой стоимости таких камней, многие розовые камни выделяются одной замечательной особенностью – они проявляют плеохроизм, то есть в зависимости от положения осмотра камня он может иметь дополнительные оттенки – оранжевый или пурпурный.

Currently, gemstones are produced by two fundamentally different technological methods - the High Pressure - High Temperature method (“HPHT”, High-pressure & High-temperature) and the Chemical Vapor Deposition (“CVD”, Chemical vapor deposition) method. The "HPHT" method is the most tested classical synthesis method, which can be used both carbon deposition on diamond from flux melts and catalytic reactions. In "CVD" synthesis, diamond growth occurs on a seed during carbon deposition mainly from a gaseous medium at relatively low temperatures and pressures.

Jewelry and precious stones are just such a category of goods, when buying which you need to pay attention to many criteria.

Sogdianite is a rather rare mineral and more often it can be found as a collection material (moreover, in systematic collections), and it is extremely rare in jewelry.