This beautiful 3.67 ct Natural Demantoid Garnet from Namibia is a collector's item. It is an unheated gemstone, with a vivid green color and SI clarity. Its diamond cut shape and 8.6x8.6 mm size make it perfect for high-end rings. The Demantoid Garnet is known for its incredible refraction, with a characteristic vivid flash phenomenon. Don't miss out on this rare find
 
Stone No: DEMTD0367
Color: Green
Clarity: SI - I
Carat Weight: 3.67
Shape : Round Brilliant
Measurement: 8.6x8.6 mm
Cut: EX
Polish: EX
Symmetry: EX
Origin: Namibia
Lab Certificate: GIA
Keytosymbols : Needle, Horsetail
Girdle : THK
 
 
The Demantoid garnet is a master of refraction boasting extremely high refraction (refractive index 1.880 to 1.889) which it does even better than the diamond.What is Demantoid Garnet and what's it worth for?
 
Demantoid Garnet is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals. Andradite is a calcium- and iron-rich garnet.
 
The chemical formula is Ca3Fe2(SiO4)3 with chromium substitution as the cause of the demantoid green color. Ferric iron is the cause of the yellow in the stone.It has the misnomer, Olivinee,and Uralian emerald. (Reference Wikipedia)
 
What is Horsetails in Demantoid Garnet and what causes this?
 
Russian demantoid oftencontainsn inclusions of chrysotile, which is a type of asbestos. These fibers radiate out from a very small crystal of chromite.These inclusions are feathery golden threads that tend to curve and resemble the tail of a horse, and are therefore referred to as horsetail inclusions. Some gemstones are more valuable for their inclusions, and 'horsetails' can be regarded as desirable features in demantoid, as they are taken as an indication of prestigious Russian origin, although some demantoids from certain other locations (such as Italy and Iran) may also contain 'horsetails', which are regarded as being characteristic of a serpentinite geographic origin and, on the other hand, not all Russian demantoids actually contain 'horsetails'. The microstructure of some demantoids is believed to be affected by the presence of 'horsetails' (the 'horsetail' typically originates towards the centre of the nodule, with the fibres branching out and radiating towards the surface), whereas horsetail-free demantoids from other sources frequently display flat crystal faces.(Ref Wikipedia).
 
Demantoid Garnet Value?
 
This is very tricky questions. of course if you have one, you are lucky to be called a collector of rare gemstone as Demantoid is extremely rare and beautiful gem.
 
Personally i like diamond cut round brilliant which is perfect cut for this gemstone.
Price based on alifgems buying and market analysis done in Thailand, Hong Kong Gem show.
 
Russian Demantoid garnet with horsetail inclusions and good clarity.
 
0.5 to 1 carat = $ 500 to $ 2000 USD
1 to 2.9 carat = $ 2000 to $ 4500 USD.
2.9 to 5 carat = $ 3000 to $ 15000 USD.
5 to 16 carat = $ 8000 to $ 75000 USD.
 
Nambia and Madagascar Demantoid garnet without horsetail inclusions and good clarity. 0.5 to 1 carat = $ 200 to $ 900 USD
1 to 2.9 carat = $ 300 to $ 1500 USD
2.9 to 5 carat = $ 800 to $ 2000 USD
5 to 16 carat = $ 1200 to $ 20000 USD