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Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Cat's Eye Opal

A variety of Opal
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Formula:
SiO2 · nH2O
A rare chatoyant form of opal showing a thin line of fire.

Visit gemdat.org for gemological information about Cat's Eye Opal.



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Unique IdentifiersHide

Mindat ID:
46783 (as Cat's Eye Opal)
3004 (as Opal)
Long-form identifier:
mindat:1:1:46783:0 (as Cat's Eye Opal)
mindat:1:1:3004:1 (as Opal)

Chemistry of Cat's Eye OpalHide

Mindat Formula:
SiO2 · nH2O
Element Weights:
Element% weight
O61.458 %
Si35.961 %
H2.581 %

Calculated from ideal end-member formula.
O
Si
H
Elements listed:
H, O, Si - search for minerals with similar chemistry

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for Cat's Eye OpalHide

References for Cat's Eye OpalHide

Reference List:

Localities for Cat's Eye OpalHide

Showing 1 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Australia
 
  • Western Australia
    • East Pilbara Shire
      • Nullagine
Simpson (1948)
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