Sapphire – Crystal Wiki
The classic gemstone from the corundum family – robust, brilliant, and timeless
Corundum (Al2O3), colored varieties as sapphire
Properties & Characteristics
Scientific Data
- Chemical Formula
- Al2O3
- Crystal System
- Trigonal
- Mohs Hardness
- 9
- Density
- 3.95–4.03 g/cm3
Physical Properties
- Color
- Blue, yellow, pink, green, colorless, and other fancy sapphires
- Luster
- Vitreous to adamantine
- Transparency
- Transparent to opaque
- Special Feature
- Very high hardness and excellent suitability for daily wear
What is Sapphire?
Sapphire refers to all non-red varieties of corundum. Besides blue, fancy sapphires are also in high demand on the market.
Formation
Sapphires form in metamorphic and magmatic environments and are often extracted from alluvial deposits.
Deposits & Market
Significant sources include Sri Lanka, Madagascar, Myanmar, Thailand, and Australia. Origin, treatment, and quality strongly influence the price.
Quality Characteristics
Color saturation, clarity, cut, light performance, and proportions are important.
Care & Handling
Very robust, yet protect jewelry from strong impacts and chemicals. Cleaning with mild soap is unproblematic.
Frequently Asked Questions
Are sapphires always blue?
No. There are numerous fancy sapphires; only red corundums are called rubies.
Are sapphires treated?
Yes, heat treatment is common and should be declared transparently.
Is sapphire suitable for daily wear?
Yes, Mohs hardness of 9 makes sapphire very suitable for everyday use.