Hydrothermal Emerald

Emerald has been synthetically grown since the late nineteenth century when the first commercially available flux grown emeralds were introduced.  Since then, a lot has changed in the methods used to ‘create’ synthetic emerald.  In general, there are two type methods; hydrothermal growth and flux growth.  Today in the Australian jewellery trade, the hydrothermally grown synthetic emeralds are the most popular as they have closer gemmological properties to natural emeralds and are cheaper to produce than the alternatively grown flux synthetic.  Another advantage of hydrothermal emerald is that the rough is able to be grown in larger sizes compared to the flux grown.  Due to the nature and slow growth of hydrothermal emeralds it is uncommon to see faceted stones larger than 12x10mm in either oval or emerald cut.


The term ‘Created Emerald’ is commonly used in the trade but should be avoided.


Mohs’ Hardness: 7.5-8
Specific Gravity: 2.67-2.73
Refractive Index: 1.567-1.578
Birefringence: 0.005-0.007
Optic Sign & Character: Uniaxial Negative
Durability: Good
Special Care: Avoid thermal shock
Synthetics: N/A
Possible Imitations: N/A