Image: James St. John (CC BY 2.0)
trigonalrareOxides
Ruby
Al2O3
This image displays a rough, deep red ruby crystal, likely still embedded in its matrix or showing natural crystal faces. Its vibrant red color is characteristic of this precious gemstone, a variety of corundum.
Ruby Physical Properties
Mohs Hardness
9Crystal System
trigonalLuster
vitreousStreak Color
whiteCleavage
none (parting sometimes observed)Fracture
conchoidalSpecific Gravity
3.97Colors
red, pinkish-red, purplish-red, orangey-redTransparency
transparentType Locality
Mogok (Myanmar), Montepuez (Mozambique), Sri Lanka, Thailand, Afghanistan, TanzaniaMineral Group
OxidesUses
jewelry, lasers, watch bearings, precision instruments, collectorAssociated Minerals
spinel, garnet, kyanite, fuchsite, margariteRarity
rareGeological Context
Ruby forms in metamorphic rocks such as marble, gneiss, and amphibolite, as well as in some igneous rocks like basalt. It is often found in alluvial deposits due to its high hardness and resistance to weathering.
