Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Category
Browse sedimentary (mineraloid specimens identified by the Rock Identifier community.
Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Yellow Chalcedony (common opal or chert variant)
Silicon Dioxide (SiO2)
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Amber
Succinite (Organic Mineraloid)
Green Opal
Hydrated Silica (SiO2·nH2O)
Limonite or Ironstone Nodule
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Limonite (Ironstone)
Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))
Abalone Shell (Nacre)
Aragonite (CaCO3) - Biogenic Mineral
White Opal
Hydrated Silica (SiO2·nH2O)
Amber
Succinite (Organic Mineraloid) - C10H16O
Amber in Matrix
Succinite (Carbon-based organic polymer)
Limonite/Ironstone
Limonite (FeO(OH)·nH2O)
Opal
Hydrated Silica (SiO2·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Limonite (Iron Stone/Ocher)
Limonite (FeO(OH)·nH2O)
Jet
Lignite (Anthracite-grade compact coal)
Opal (in Jewelry Setting)
Hydrated Silicon Dioxide (SiO2·nH2O)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Opalite
Man-made opalescent glass
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Common Opal
SiO2·nH2O (Hydrated Silicon Dioxide)
Green Opal
Hydrated amorphous silica (SiO2·nH2O)
Amber
Succinate (Fossilized Tree Resin)
Opal
Hydrated silica (SiO2 · nH2O)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Amber
Amber (C10H16O)
Limonite (Ironstone)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Amber
Succinate (Fossilized Tree Resin)
Opal
Hydrated Silica (SiO2·nH2O)
Amber (Copal)
Succiniferous Resin
Opal
Hydrated amorphous silica (SiO2·nH2O)
Amber
Succiniferous fossil resin (C10H16O)
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Opalite
Synthetic Glass (Amorphized Silicon Dioxide)
Black Opal
Hydrated silica (SiO2·nH2O)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber (Copal)
Fossilized Tree Resin
Opal
Hydrated silica (SiO2 "NH2O)
Amber (and Cubic Zirconia)
Fossilized Tree Resin