Opal
Common Opal Precious Opal Imitation / Synthetic Opal Common Opal Precious Opal Imitation / Synthetic Opal
10 – Mineraloids
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- 09 – Silicates
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- 09C – Cyclosilicates
- 09D – Inosilicates
- 09E – Phyllosilicates
- 09F – Tectosilicates
- 10 – Mineraloids
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