1 pcs Blue Tanzanite - 9.99 ct - Antwerp Laboratory for Gemstone Testing (ALGT)
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Natural Tanzanite gemstone, one stone, 9.99 carats, blue, semi-transparent, commonly heated with no evidence of treatment, ALGT report.
AI-assisted summary
Description from the seller
ALGT COLORED STONE IDENTIFICATION REPORT
IDENTIFICATION
Species ......................................................................................................... Natural Zoisite
Variety ..................................................................................................................... Tanzanite
DESCRIPTION
Shape & Cutting Style ................................................ Modified Octagon, Step Cut
Measurements .................................................................... 11.81 x 10.24 x 8.53 mm
Carat Weight ...................................................................................................... 9.99 Carat
Color ..................................................................................... Intense/Vivid Purplish Blue
Transparency ....................................................................................... Semi-transparent
ADDITIONAL GRADING CHARACTERISTICS
Origin ......................................................................................................................... Tanzania
Origin determination is an expert opinion based on microscopic examination, spectroscopic features and
chemical trace element analysis.
COMMENTS
Tanzanite is commonly heated at low temperature to improve its color.
There is currently no scientific method available to determine whether this
gemstone has been enhanced or not.
Moderate amount of clarity enhancement in fissures.
Clarity enhancement has become a common practice in trade for many
gemstones. This enhancement is reversible at any time.
17 November, 2025
95638353
ALGT COLORED STONE IDENTIFICATION REPORT
IDENTIFICATION
Species ......................................................................................................... Natural Zoisite
Variety ..................................................................................................................... Tanzanite
DESCRIPTION
Shape & Cutting Style ................................................ Modified Octagon, Step Cut
Measurements .................................................................... 11.81 x 10.24 x 8.53 mm
Carat Weight ...................................................................................................... 9.99 Carat
Color ..................................................................................... Intense/Vivid Purplish Blue
Transparency ....................................................................................... Semi-transparent
ADDITIONAL GRADING CHARACTERISTICS
Origin ......................................................................................................................... Tanzania
Origin determination is an expert opinion based on microscopic examination, spectroscopic features and
chemical trace element analysis.
COMMENTS
Tanzanite is commonly heated at low temperature to improve its color.
There is currently no scientific method available to determine whether this
gemstone has been enhanced or not.
Moderate amount of clarity enhancement in fissures.
Clarity enhancement has become a common practice in trade for many
gemstones. This enhancement is reversible at any time.
17 November, 2025
95638353
Details
Nr of stones
1
Gemstone type
Tanzanite
Total carat weight
9.99
Gemstone colour
Blue
Transparency
Semi-transparent
Treatment
Commonly heated with no evidence of treatment
Laboratory Report
Antwerp Laboratory for Gemstone Testing (ALGT)
Sealed by laboratory
No
Shape
Octagon
Cutting style
Step cut
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