blue topaz

Blue Topaz

Naturally occurring Blue Topaz is quite rare. Typically, colourless, grey or pale yellow and blue material is heat treated and irradiated to produce a more desired shade of blue. Blue Topaz is a very pretty stone, usually available in three different hues, Sky Blue (pale), Swiss Blue (medium) and London Blue (dark). Blue was once the rarest colour of the Topaz family but today it is the most common, thanks to the irradiation colour enhancement process developed in the 1970′s. It is both affordable and available in a wide range of shapes and sizes.

Stock Sizes: Available in Faceted including checkerboard and buff top and Cabochon
Round: 1.25mm – 20mm
Oval: 3x2mm – 25x18mm
Marquise: 4x2mm – 25x12mm
Octagon: 4x3mm – 25x18mm
Octagon/Radiant: 4x3mm – 20x15mm + 8mm – 10mm
Trillion: 3mm – 16mm
Hexagon: 4mm – 10mm + 5x3mm – 10x6mm
Square: 1.5mm – 16mm
Triangle: 3mm – 8mm
Heart: 3mm – 18mm
Pear: 4x3mm – 25x20mm
Princess cut: 2mm – 11mm
Baguette: 3x2mm – 20x5mm
Baguette/Radiant: 4x2mm – 8x4mm
Cushion: 4mm – 14mm + 5x3mm – 20x15mm

Large selection of non-calibrated and free form sizes also available

Chemical Formula: Al2SiO4(F,OH)2
Crystal Structure: Orthorhombic
Colour: Sky (pale), Swiss (medium), London (dark)
Hardness: 8 on Moh`s scale
Refractive Index: 1.609 – 1.643
Specific Gravity: 3.49 – 3.57
Cleavage: Perfect

Treatments: Irradiation and Heating

Care: Blue topaz is quite a resilient gemstone and is considered tough and durable and will not dissolve in most chemical solvents. The irradiation and heat enhancements do not affect its durability. This combination of irradiation and annealing is considered stable. Topaz has perfect cleavage which can make it prone to chipping or forming flaws if banged hard. As with most gemstones, Blue Topaz should be kept away from sudden extreme temperature changes as these conditions can cause permanent changes to the stone’s colouration. Blue Topaz is best cleaned with warm soapy water and a soft brush avoiding Ultrasonic cleaners and steamers.