Zircon (hardness: 7.5 Mohs)
Zirconium silicate
Specific gravity: 4.6-4.7
Jargon: Variable
Matura diamond: Colorless
Hyacinth: Yellow, orange, red, brown
The Hooker Emerald, Colombia.
Birthstones
| Month of birth | Gemstone | Color |
|---|---|---|
| January | Garnet | Dark red |
| February | Amethyst (Quartz) | Purple |
| March | Aquamarine (Beryl) or Bloodstone (Quartz) | Pale blue |
| April | Diamond or Rock Crystal (Quartz) | Colorless |
| May | Emerald (Beryl) | Bright green |
| or Chrysoprase (Quartz) | Pale green | |
| June | Pearl or Moonstone (Feldspar) | Cream |
| July | Ruby (Corundum) or Carnelian (Quartz) | Red |
| August | Peridot | Pale green |
| or Sardonyx (Quartz) | Brown and white | |
| September | Sapphire (Corundum) | Pale to dark blue |
| or Lapis Lazuli | Deep blue | |
| October | Opal or Tourmaline | Variegated |
| November | Topaz or Citrine (Quartz) | Yellow |
| December | Turquoise | Sky blue |