Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Category
Browse mineral health specimens identified by the Rock Identifier community.
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
Banded Gneiss
Gneiss (high-grade metamorphic silicate rock)
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)
Foliated Metamorphic Rock (likely Gneiss or Schist)
Gneissic Metamorphic Rock
Gneiss
Gneiss (high-grade metamorphic rock)
Quartz-rich pegmatite, likely with iron staining
Granitic pegmatite, chiefly quartz (SiO₂) and feldspar, with possible mica and iron oxides
Mica-rich metamorphic rock, likely schist
Muscovite–biotite schist, possibly with quartz and feldspar
Mica Schist
Schist (primarily Muscovite and Biotite mica)
Limonite Concretion
Limonite (FeO(OH)·nH2O) Pseudomorph
Limonite (Iron Ore)
Hydrated ferric oxide mixture (FeO(OH)·nH2O)
Weathered schist
Mica schist, typically quartz–mica schist
Red Sandstone (Iron-stained)
Clastic sedimentary rock (primarily Quartz with Iron Oxides)
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Polished bumblebee jasper bead
Bumblebee jasper (trade name); chiefly calcite, aragonite, and pyrite, with variable realgar/orpiment and other minerals
Weathered granite or granitic gneiss
Granite; chiefly quartz, feldspar, and mica, possibly with gneissic foliation
Garden Quartz (Lodalite)
Silicon Dioxide with various mineral inclusions (SiO2)
Polished agate geode slice
Microcrystalline quartz (chalcedony), SiO₂, with possible quartz-lined or calcite-filled cavity
Citrine
Silicon Dioxide (SiO2)
Mixed Mineral and Fossil Collection
Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)
Amethyst
Quartz (Silicon Dioxide, SiO2)
Healer's Gold (Iron-Stained Quartz Cluster)
Silicon Dioxide with Iron Oxide Coating (SiO2)
Geode
Quartz / Chalcedony nodule
Peach Quartz
Silicon Dioxide (SiO2)
Amethyst Cluster
Silicon Dioxide (Quartz variety: Amethyst) - SiO2
Quartz Geode
Silicon Dioxide (SiO2)
Blue Quartz
Silicon Dioxide (SiO2) with inclusions
Likely granitic gneiss pebble
Quartz–feldspar–biotite gneiss (visual identification; exact type uncertain)
Mica Schist / Granite
Mica Schist (Silicate metamorphic rock)
Fluorite
Calcium Fluoride (CaF2)
Limonite (Iron Ore / Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Limonite
FeO(OH)·nH2O
Selenite (variety of Gypsum)
Calcium sulfate dihydrate (CaSO4·2H2O)
Merlinite (dendritic opal)
Common opal (hydrated amorphous silica, SiO₂·nH₂O) with dark manganese-oxide dendrites; the trade name “merlinite” is also applied to other patterned stones.
Morganite and Aquamarine (Beryl) Bracelet
Beryllium aluminum silicate, Be3Al2(SiO3)6
Bicolor Quartz Tumble
Silicon Dioxide (SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
Hematite (likely Botryoidal or Specularite variant)
Iron(III) oxide (Fe2O3)
Hematite
Iron(III) oxide (Fe2O3)
Hematite
Hematite (Iron(III) oxide, Fe2O3)
Native Copper Nugget
Native Copper (Cu)