Difference between revisions of "Fire opal"
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girasol; Mexican opal; water opal; jelly opal; opala de fogo (Port.); Feueropal (Deut.) | girasol; Mexican opal; water opal; jelly opal; opala de fogo (Port.); Feueropal (Deut.) | ||
| − | == | + | == 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. |
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| + | ==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" | {| class="wikitable" | ||
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! scope="row"| Density | ! scope="row"| Density | ||
| − | | 2.1-2.3 | + | | 2.1-2.3 g/ml |
|- | |- | ||
! scope="row"| Refractive Index | ! scope="row"| Refractive Index | ||
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|} | |} | ||
| − | == | + | ==Resources and Citations== |
| − | + | * Mineral Galleries at http://mineral.galleries.com/minerals/mineralo/opal/opal.htm Mohs hardness=5.5-6.0 | |
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| − | * | ||
| − | * Wikipedia | + | * 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 | * Yasukazu Suwa, ''Gemstones: Quality and Value, Volume 1'', Sekai Bunka Publishing Inc., Tokyo, 1999 Comment: RI=1.450; Specific gravity=2.15 | ||
Latest revision as of 08:28, 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