THE MATERIAL LIBRARY
Ruby
Red corundum, the same mineral species as sapphire.
Colors & patterns
Pinkish red to deep red, sometimes with visible inclusions.
Typical origins
Sources include Myanmar, Mozambique, Sri Lanka and other countries.
Hardness
9 on the Mohs scale.
Choosing & setting this material
Some cabochons show a star, but most do not. Heating, filling and laboratory-grown material are important disclosures; filled ruby requires more cautious care.
Care & cleaning
Clean gently with lukewarm water, a little mild soap and a soft cloth, then dry. Avoid steam, ultrasonic cleaners, harsh chemicals and sudden temperature changes, especially when treatments are unknown.
Origins above describe typical sources of the material, not the origin of an illustrated or stocked stone. Hardness measures scratch resistance, not resistance to breaking. Confirm the identity and treatments of the actual piece.
Further reading: Material reference · GIA: gem treatments