Star-stone
| Star-stone at a Glance | ||
|---|---|---|
| Material Type | Gems | |
| Colors | Red, Blue, Pink, Yellow, Green, Purple, White | |
| Rarity | Common | |
| Cultural Relevance | None | |
| Required for Alterations | No | |
A characteristic in some gemstones is called asterism. An asterism is a "star-shaped" concentration of reflected or refracted light from a gemstone. This characteristic can appear when suitable stones are cut en cabochon (ie: shaped and polished, not faceted.) Gemstones that exhibit this effect are referred to as asteria or star-stone.
The star-effect (asterism) is caused by a difference in refractive properties between the host material and that of the dense inclusions of rutile or "silk" (read: titanium dioxide). The stars are caused by light reflecting from needle-like inclusions of rutile aligned perpendicularly to the rays of the star -- though it may also be caused by inclusions of hematite such as in black star sapphire. Some star sapphires contain both hematite and rutile, resulting in a 12-ray star to appear.
There are two types of asterism:
- Epiasterism - seen in sapphire and most other gems. This is the result of a reflection of light on parallel arranged inclusions inside the gemstone.
- Diasterism - seen in rose quartz. This is the result of light transmitted through the stone. In order to see the asterism effect at all, the stone must be illuminated from behind. (Rose quartz also exhibits epiasterism.)
- Some Asteria (star-stone) Gems
- star chrysoberyl
- star cymophane
- star citrine
- star emerald
- star garnet
- star moonstone
- star rose quartz
- star ruby
- star sapphire
- star spinel
- Unique star stones
Alteration Rules
This material is not required for alterations.
Raw Material Sources
Corik's Secret: Treasures of the Tomb/End loot, Cut silver gem case set with polished cabochon stones, Platinum filigree jewelry box with glaes fittings and Polished goldbark gem case set with marquis topaz of myriad sizes
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