YAG (yttrium aluminium garnet) is a lab grown material first introduced as a diamond simulant. It was marketed under various names such as, diamonair and diamonique. It is now less used as a diamond simulant, being replaced by cubic zirconia (CZ) which has a much higher dispersion (exceeding that of diamond). It is made in different colours to simulate sapphire, emerald and other gemstones. During manufacture chemical elements are added to determine the colour, for example - chromium for green, cobalt for blue and titanium for yellow. It is a durable stone with good clarity and colour saturation, it also has an exceptional lustre.

Properties and Additional Information

Gemstone type: Manufactured - Lab grown simulant.
Crystal System: Cubic (isometric)
Chemical Composition: Yttrium Aluminium Garnet, Y3AL5O12
Colour: Various colours
Lustre: Bright vitreous to sub-adamantine.
Pleochroism: Absent
Dispersion: Medium
Hardness: 8 1/2 on the Mohs' scale.
Toughness: Good
Cleavage: None
Density in gm/cc: 4.55
Double refraction: No
Refractive index: 1.833

Common Treatments

YAG is not normally treated.