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| Quartz | |||
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Quartz SiO2 cut amethysts from Minas Gerais, Brazil. |
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Quartz SiO2 aventurine from India. |
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Quartz SiO2 chrysoprase from Australia. |
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Quartz SiO2 chrysoprase from Zabkowice Slaskie (former: Frankenstein), Silesia, Poland. |
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Quartz SiO2 citrine from Brazil. |
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Quartz SiO2 ferriferous quartz from the Anna Mine, Alicante, Spain. |
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Quartz SiO2 mineral blossom with porous hematite from Eiserfeld, Siegen, Germany. |
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Quartz SiO2 prase from India. |
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Quartz SiO2 rock crystal from Diamantina, Brazil. |
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Quartz SiO2 rosy quartz from Custer, South Dakota, USA. |
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Quartz SiO2 smoky quartz from the Habachtal, Austria. |
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Quartz SiO2 tiger's-eye from the Oranje River, Griqualand, South Africa. |
| Calcedony | |||
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Calcedony SiO2 agate from the Weiselberg, Saargebiet, Germany. |
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Calcedony SiO2 agate from Rio Grande del Sul, Brazil. |
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Calcedony SiO2 agate from Rio Grande del Sul, Brazil. |
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Calcedony SiO2 enhydros from Catalan, Uruguay. |
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Calcedony SiO2 heliotrope from Nishapur, Persia. |
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Calcedony SiO2 thunderegg agate from the Priday Ranch, Oregon, USA. |
| Opal | |||
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Opal SiO2 · n H2O precious opal from Queensland, Australia. |
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Opal SiO2 · n H2O precious opal from White Cliffs, Australia. |
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Opal SiO2 · n H2O precious opal from Australia. |
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Opal SiO2 · n H2O fire opal from Querretoro, Mexico. |
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Opal SiO2 · n H2O geyserite from the Yellowstone Park, Wyoming, USA. |
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Opal SiO2 · n H2O hyalite from Esperies, Hungary. |
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Opal SiO2 · n H2O hyalite from San Luis Potosi, Mexico. |
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Opal SiO2 · n H2O "Prasopal" from Zabkowice Slaskie (former: Frankenstein), Silesia, Poland. |
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Opal SiO2 · n H2O wood opal (silified wood) from El Paso County, Colorado, USA. |
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Opal SiO2 · n H2O wood opal (silified wood) from Arizona, USA. |
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