Aquamarine is the green-blue to blue variety of the mineral beryl. Emerald and morganite belong to the same species.
Properties
| Refractive index | 1.577 to 1.583 (GIA); 1.567 to 1.590 (IGS) |
|---|---|
| Birefringence | 0.005 to 0.009 (GIA); typical aquamarine 0.005 to 0.006 (LibreTexts), 0.005 to 0.007 (IGS) |
| Optic character | Doubly refractive (uniaxial) |
| Dispersion | 0.014 |
| Specific gravity | 2.72 (GIA); 2.66 to 2.80 (IGS) |
| Hardness (Mohs) | 7.5 to 8.0 |
| Crystal system | Hexagonal |
| Pleochroism | Weak to moderate: blue, colorless |
| Absorption spectrum | Broad band in the violet, 427 nm (Fe); diffuse band in the blue, 456 nm; weak band, may be seen, 537 nm |
Published values. They change a little from stone to stone. Our tools do not model aquamarine yet. Sources: GIA · International Gem Society · LibreTexts Gemology
In more detail
Its color is usually a light pastel greenish blue, and heat treatment usually makes it more blue. In the market, it competes with blue topaz, whose color comes from radiation treatment. Aquamarine is durable enough for daily wear, but keep it away from heat. Ultrasonic and steam cleaners are usually safe, except for stones with liquid inclusions or fractures.
Related terms
- Beryl: Beryl is the mineral species of emerald. Aquamarine and the other beryl colors belong to the same species.
- Emerald: Emerald is the green to bluish green variety of the mineral beryl. Chromium, vanadium or both cause its color.
- Morganite: Morganite is the pink variety of the mineral beryl. Traces of manganese cause its color.
- Topaz: Topaz is a gem mineral with an exceptionally wide color range. Impurity elements or defects in its crystal structure cause its color.
- Heat treatment: Heat treatment is controlled heating of a gem to change its color or clarity.