Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Category
Browse mineraloid (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Green Opal
Hydrated Silica (SiO2·nH2O)
Ethiopian Opal (Welo Opal)
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
Sea Glass (Frosted Quartz/Glass)
Amorphous Silicon Dioxide (SiO2)
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Carnelian
Carnelian (SiO2)
Agate Geode
Cryptocrystalline Quartz (SiO2)
Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles
Mixed gemstones (primarily Silicon Dioxide - SiO2)
Jasper (yellow/cream variety)
SiO₂ (Cryptocrystalline Quartz)
Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
Chalcedony
Cryptocrystalline Quartz (SiO2)
Onyx
Chalcedony (SiO2) with parallel banding
Quartz (likely a form of massive or vein quartz)
Quartz (SiO₂)
Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
Gray Agate with Druzy Quartz Geode
Cryptocrystalline Quartz (SiO2)
Banded Agate (Carnelian variety)
Cryptocrystalline Quartz (SiO2)
Banded Agate
Cryptocrystalline Quartz (SiO2)
Chert (Common Opal/Jasper variety)
Cryptocrystalline Quartz (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (specifically Brown Chert or Flint)
Cryptocrystalline Quartz (SiO2)
Chert (varietal: Flint/River Pebble)
Cryptocrystalline Quartz (SiO2)
Banded Agate
Cryptocrystalline Quartz (SiO2)