Difference between revisions of "Fire opal"

Latest revision as of 07:28, 21 August 2022

Description

A brilliant red and orange Opal. Fire opals have been mined in Mexico for over 500 years. Current mines in Mexico are at Queretaro and Magdalena.

Synonyms and Related Terms

girasol; Mexican opal; water opal; jelly opal; opala de fogo (Port.); Feueropal (Deut.)

Risks

Highly hydrated; may be subject to dehydration and surface cracking.

Physical and Chemical Properties

Mineral system=amorphous
Cleavage=none
Fracture=conchoidal
Luster=vitreous to resinous
Streak=white
Fluoresce=usually white or pale green, some samples phosphoresce

Composition	SiO2·nH2O
Mohs Hardness	5.5-6.0
Density	2.1-2.3 g/ml
Refractive Index	1.44-1.46

Resources and Citations

Mineral Galleries at http://mineral.galleries.com/minerals/mineralo/opal/opal.htm Mohs hardness=5.5-6.0

Wikipedia: http://en.wikipedia.org/wiki/Opal (accessed Oct. 12, 2005) specific gravity=2.1=2.3; RI=1.44 -1.46; Mohs hardness=5.5-6.6

Yasukazu Suwa, Gemstones: Quality and Value, Volume 1, Sekai Bunka Publishing Inc., Tokyo, 1999 Comment: RI=1.450; Specific gravity=2.15

Michael O'Donoghue and Louise Joyner, Identification of Gemstones, Butterworth-Heinemann, Oxford, 2003 Comment: RI=1.45; Specific gravity=2.10

Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

@@ Line 7: / Line 7: @@
 girasol; Mexican opal; water opal; jelly opal; opala de fogo (Port.); Feueropal (Deut.)
-== Other Properties ==
+== Risks ==
-Mineral system=amorphous  Cleavage=none  Fracture=conchoidal  Luster=vitreous to resinous   Streak=white   Fluoresce=usually white or pale green, some samples phosphoresce
+Highly hydrated; may be subject to dehydration and surface cracking.
+==Physical and Chemical Properties==
+* Mineral system=amorphous
+* Cleavage=none
+* Fracture=conchoidal
+* Luster=vitreous to resinous
+* Streak=white
+* Fluoresce=usually white or pale green, some samples phosphoresce
 {| class="wikitable"
@@ Line 20: / Line 29: @@
 |-
 ! scope="row"| Density
-| 2.1-2.3
+| 2.1-2.3 g/ml
 |-
 ! scope="row"| Refractive Index
@@ Line 26: / Line 35: @@
 |}
-== Hazards and Safety ==
+==Resources and Citations==
+* Mineral Galleries at http://mineral.galleries.com/minerals/mineralo/opal/opal.htm   Mohs hardness=5.5-6.0
-Higly hydrated; may be subject to dehydration and surface cracking.
-== Additional Information ==
-Mineral Galleries: [http://mineral.galleries.com/minerals/mineralo/opal/opal.htm Website]
-== Sources Checked for Data in Record ==
-* Website address 1  Comment: Mineral Galleries at http://mineral.galleries.com/minerals/mineralo/opal/opal.htm   Mohs hardness=5.5-6.0
-* Wikipedia, the free encyclopedia, at http://www.wikipedia.com  Comment: http://en.wikipedia.org/wiki/Opal (accessed Oct. 12, 2005) specific gravity=2.1=2.3; RI=1.44 -1.46; Mohs hardness=5.5-6.6
+* Wikipedia: http://en.wikipedia.org/wiki/Opal (accessed Oct. 12, 2005) specific gravity=2.1=2.3; RI=1.44 -1.46; Mohs hardness=5.5-6.6
 * Yasukazu Suwa, ''Gemstones: Quality and Value, Volume 1'', Sekai Bunka Publishing Inc., Tokyo, 1999  Comment: RI=1.450; Specific gravity=2.15