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London Blue Topaz 190.30 ct

Availability: In stock


This huge oval london blue Topaz from Brazil weights 190.30 carats. This london blue Topaz has been given the clarity class 'Eye Clean' and is priced at only 2369.00 USD (12.44$ / CT). It has undergone irradiation treatment to improve the color.

General Mineral Informations
 Mineral:  Topaz
 Mohs Hardness:  8
 Specific Gravity:  3.49–3.57
 Refractive Index:  1.606-1.644

London Blue Topaz 190.30 ct

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Additional Information

Type Facet
Carat 190.34
Measurements in mm No
Clarity Class Eye Clean
Treatment irradiation treatment
Shape Oval
Origin Brazil


White Topaz, a silicate mineral, is an unexpensive yet beautiful gemstone often used for jewellry. Colourless Topaz specimens undergo a radiation treatment to achieve one of the three colour hues used to describe the colour intensity of the blue Topaz: Sky Blue, Swiss Blue, London Blue.

Topaz has been known to mankind for at least 2000 years but it wasn't until past century that Topaz specimens were irradiated and blue Topaz became widely available on the gem market.


Clarity Classes


Loupe Clean   Under 10x magnification are no inclusions visible. Very Slightly Included   Within the gem are small inclusions that are visible on close  examination.
Almost Loupe Clean   Small inclusions are visible using a 10x magnification  loupe Slightly Included   SmallInclusions are visible without close inspection.
Eye Clean   Inclusions are not visible to the naked eye. Moderately Included   In the gemstone are larger inclusions that are easily visible.
Almost Eye Clean   Inclusions in the gem are difficult to detect with the naked  eye. Included   In the gem are many visible inclusions.