Natural Gemstones: Reference Facts
Fire Opal
The ancient Latin name for opal was "Opalus", which was derived from the Sanskrit word "Upala" meaning "precious stone". There are several types of opal. Opal with a play-of-color is called precious opal. Common opal is opal with no play-of-color and often translucent to opaque. Red and orange opal is normally called 'Fire Opal'. Fire opal can be easily recognized by its yellow-orange-red body color. This type of opal is transparent to translucent with little or no play-of-color. Mexico is the main source of fire opal, and a recent discovery in Brazil provides a fresh accent in the world of gemstones.
The warm and fiery color of fire opal gave this gemstone its name. The most valued fire opal is reddish orange, transparent and highly saturated. Rather than cut en cabochon, fire Opal is typically faceted as gemstone.
Fire opal is a gemstone for people who are active and enjoy life. Fire opal is said to bring good fortune, well-being, peace and harmony. Fire opal is also thought to give courage, energy and endurance to the wearer. Fire Opal is the alternate birthstone for October and is the suggested gift for the 14th anniversary.
| Fire Opal Known Facts
|
| Color |
Red, Reddish Orange, Orange, Brownish Orange, Yellow-Orange, Yellow |
| Clarity
|
Type I – usually eye clean and very high clarity under magnification
|
| Crystal Structure
|
Amorphous
|
| Chemical Composition
|
SiO2nH2O – Hydrated silica gel |
| Luster
|
Vitreous
|
| Optic Character
|
Singly Refractive
|
| Durability
|
Good
|
| Specific Gravity(SG)
|
2.1
|
| Refractive Index(RI)
|
1.45 +0.02; -0.077
|
| Birefringence
|
-
|
| Hardness
|
6
|
| Occurrence
|
Mexico, Brazil |
|
|
