Topaz is an aluminum silicate and fluorine. Topazes can be found in a multitude of different colors, but Swiss Blue topaz blue is very popular and appreciated. These different colors are due to elements involved in the chemical composition of topaz: iron, chromium, magnesium or titanium. This fine synthetic stone is appreciated since ancient times, its name would come from the Sanskrit word "Tapaz" for "fire", indeed, it was believed endowed with the ability to make invincible the one who bore it. The blue topaz (or Swiss blue) is the birthstone of the natives of December.
Origin of topazes
Topaz are found in several parts of the world: Sri Lanka, Madagascar, Myanmar, USA, Pakistan, Brazil, Russia, China, Nigeria and other countries whose production is lower. The most important deposit is located in the state of Minas Gerais in Brazil where we find topazes of all colors including the imperial topaz (orange-red) which is exclusively extracted from two mines in this region. Natural pink topaz is extracted in North Pakistan and Russia. Finally, the very pale or pale blue topaz used to obtain the blue topaz (and in particular the beautiful Swiss blue topaz) is extracted from Brazil, Sri Lanka, China and Nigeria.
The color of a topaz
Topaz exists in almost all colors: white, blue, green, yellow, orange, red, pink, purple and even multicolored. The most famous and common are the topaz London blue; we find very light pastel blue to the "Swiss blue", a beautiful intense and vibrant blue sky. It is magnesium, titanium and iron that are at the origin of the colors yellow, brown and blue. The chrome element is causes the colors pink, red and purple. Topaz is a pleochroic gem, which means that its shades vary according to the angle of vision and thus gives a lot of glare and shine to the stone. Some Topazes may become bland when exposed to intense light radiation, so avoid exposing these gems to direct sunlight.
The purity
White zircon is a natural mineral, so it is imperfect and has more or less visible inclusions. These inclusions are natural features, and allow verifying the authenticity and origin of the stone. In a stone of good quality, the inclusions are tiny, and it is only with a microscope x10 that we can distinguish them. The purity of wholesale loose gemstones will be determined by the quantity and arrangement of its inclusions. Most good topaz does not have inclusions visible to the naked eye.
There are thermal treatments for magnifying topaz that are perfectly accepted by the major recognized laboratories of expertise. The colorless or very light blue stones, present in large quantities in Brazil, are very often heated to 300C ° in order to obtain gems of an intense blue: the sublime topazes of Swiss blue color. This treatment is durable over time and does not alter the stone. Some topazes may lose their color saturation in daylight. The original color can be restored by X-ray radiation.
Article Source: https://wholesaleloosegemstones.wordpress.com/2019/06/26/a-complete-guide-about-wholesale-loose-gemstones-the-topaz-stone/