Sapphire
Variety of corundum
Very Rare · Al₂O₃
Corundum coloured blue by iron and titanium impurities. The same mineral species as ruby, distinguished only by colour. Formed in metamorphic and igneous environments, often recovered from alluvial deposits.
Identity
- Formula
- Al₂O₃
- Chemical class
- Oxide
- Mineral group
- Corundum, Ruby
- Also known as
- Blue corundum
- Used in alchemy
- Sapphire Powder
Crystallography
- Crystal system
- Trigonal
- Habits
- Tabular, Prismatic, Pyramidal
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 9
- Density
- 4 g/cm³
- Luster
- Vitreous, Adamantine
- Colors
- blue, sky blue, dark blue, yellow, pink, colorless, orange
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Metamorphic, Igneous
- Host rocks
- Granite, Volcanic rock, Marble, River gravels and sands
- Associated minerals
- Spinel, Rutile, feldspar, Nepheline
- Found in
- Pegmatite deposit, Placer deposit
- Geography
- Sri Lanka, Myanmar, Madagascar, Australia, India (Kashmir)
Classification
- Rarity
- Very Rare
- Gem quality
- Yes
Arcane properties
- Affinity
- Water, Air
- Effects
- Scrying, Mind
- Planar origin
- Material Plane
Sources
- Sapphire. Mindat.org (Hudson Institute of Mineralogy).
- Corundum. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Corundum. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Sapphire. Gemdat.org (Hudson Institute of Mineralogy).
- Sapphire Description. Gemological Institute of America, Gem Encyclopedia.
- Gaston Giuliani, Lee A. Groat, Geology of Corundum and Emerald Gem Deposits: A Review. Gemological Institute of America, Gems & Gemology, 2019.
Browse the Crystal Encyclopedia — MGS Toolbox