Andamooka-South Australia mining area know for its treated matrix and crystal opal

Black Opal-A solid crystal opal that while black in color shows a play of color in its transparency.

Boulder Opal-a seam of opal that is attached to its host matrix.

Boulder Matrix Opal- Opal that has formed in freeform patterns, flowing through and mixing with the host material to form unique patterns.

Coober Pedy-South Australias major opal producer and home of white base precious
Opal.

Crystal Opal- A solid opal that is transparent with play of color.

Doublet-An opal that has had another material glued to its back, usually either for strength support or color enhancement.

Fire Opal-An opal that is a solid colored crystal, generally red or orange and shows no playof color.

Gilson Opal-A synthetic opal created by Pierre Gilson

Jelly Opal-A solid opal, transparent crystal material, but with no play of color usually seen in

a red or orange colorbut not limited to these colors..

Lightning Ridge-In the New South Wales area, is world famous for its Black Opal.

Mintabie-Located in South Australia, this mining area is best known for its black seam
opal and crystal opal.

Potch-Another name for common opal.

Yowah-Matrix Opal usually found in a "nut" ranging in size from a pea to a
football. Opal can be common to precious opal with exquisite patterns.

Opal Patterns:
1. Broad Flashfire-Sheets of fire (COLOR) seen across the face of the stone.
2. Fire Pattern-Created by the play of color in the stone.
3. Flash Fire-A pattern showing areas of color, overlapping in various sizs and colors.
4. Harlequin-Squares or blocks of fire (color )set closely together.
5. Precious Opal-A display of color in a distinctive pattern.
6. Pin Fire-Small pinpoints of color seen in the base color.
7. Rolling Flashfire-When color rolls across the face of the stone as it is moved.