Topaz

Color: blue, yellow, pink, red, brown, green, colorless Hardness: 8 Refractive index: 1.60 - 1.64 Density: 3.50 - 3.58 Chemical composition: Al2[SiO4](F,OH)2 Crystal structure: orthorhombic Origins: Brazil, Madagascar, Russia, USA, Mexico, Pakistan. Most valued color for topazes is orangey pink (imperial topaz from Brazil). Heat treatment is usual for yellowish stones; color of light blue or colorless stones can be enforced by x-ray treatment and heating. Very big clean crystals are common. Prices subject to noticeable variation due to fashion trends on local markets.

Market values of Topaz  

Historical values