Gemstone Encyclopedia

Sphalerite: The Fiery Gem of Brilliance and Light

Sphalerite carries more than three times the fire of a diamond, with dispersion of 0.156 that no collectible gem approaches. Learn why transparent crystals are freak occurrences in zinc ore, why cu...

Sphene: The Fiery Gemstone with Unmatched Brilliance

Sphene, officially titanite, combines fire beyond diamond with the strongest facet-doubling effect in gemology, an interior that seems to move. Learn how its optical trio works, why chrome green st...

Spinel: The Hidden Treasure Among Gemstones

The most famous ruby in the British Crown Jewels is a spinel, and so are most of history's greatest red stones. Learn why spinel impersonated ruby so perfectly, why it reaches the market untreated ...

Tanzanite: The Mysterious African Gemstone, Its History, Legends, and Investment Value

Tanzanite begins with a Maasai legend of fire, a tailor who thought he found sapphire, and a Tiffany campaign that renamed a mineral. One hill below Kilimanjaro supplies the entire world, the depos...

Zircon: The Brilliant Gemstone with a Rich History

Zircon is a natural gem with fire approaching diamond and a pedigree reaching 4.4 billion years, sharing nothing with synthetic cubic zirconia but a syllable. Learn how radioactivity creates two ge...