Real vs fake: Ruby
Fine ruby is red corundum. Red spinel, garnet, and glass are classic lookalikes in trade — refractive behavior and inclusions separate them.
- Hardness 9 — scratches topaz and quartz
- Strong red fluorescence common (esp. Myanmar)
- Silk or fingerprint inclusions in naturals
- Dichroscope: red / orangey-red
- Glass bubbles or swirled flow lines
- Garnet is singly refractive and usually darker
- Spinel lacks ruby’s typical fluorescence pattern
- Rounded facet junctions on cheap glass
Field tests
- Refractometer RI ~1.76–1.78 for ruby
- Polariscope / dichroscope for optical character
- Lab report recommended above modest carat weights