Turquoise and Hematite
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Hematite (Fe2O3)
mineral
Category
Mineral Composite
Browse mineral composite specimens identified by the Rock Identifier community.
Learn about Mineral Composite in the encyclopedia
View all →
Gneiss (River Cobble)
Gneiss
metamorphic
Banded gneiss pebble
Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole
metamorphic
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Pyrite (or Arsenopyrite / Ore mineral aggregate)
FeS2 (Iron Sulfide)
mineral
Diamond
Carbon (C)
gemstone
Peridotite (Dunite)
Olivine-rich Peridotite ((Mg,Fe)2SiO4)
igneous
Granite
Granite
igneous
Note regarding baguette production (not a rock)
Digital text image - Somali language
not a rock
Agate / Chalcedony Geode
Silicon Dioxide (SiO2)
sedimentary
Granite Gneiss
Gneiss (Derived from Granite protolith)
metamorphic
Schist (Greenschist / Mica Schist)
Metamorphic rock rich in platy minerals (e.g., Chlorite/Mica schist)
metamorphic
Amygdaloidal Basalt
Extrusive Igneous Rock with Amygdules
igneous
Potassium Feldspar (Orthoclase / Microcline)
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Quartz (Druzy or Chalcedony variant)
Silicon Dioxide (SiO2)
mineral
Vesicular volcanic rock, likely scoria
Scoria; composition commonly basaltic to andesitic, rich in plagioclase and pyroxene
igneous
Fossilized Stingray Mouth Plate
Myliobatidae gen. et sp. indet. (e.g., Myliobatis, Aetobatus)
fossil
Unakite
Altered Granite (Epidotized Granite)
metamorphic
Granite Glacial Erratic
Intrusive Phaneritic Felsic Rock (Granite)
igneous
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Greenschist (Chlorite Schist)
Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)
metamorphic
Limonite on Sandstone
Iron Oxyhydroxide (FeO(OH)·nH2O) on Quartz Sandstone
sedimentary
Quartz (Druzy / Crystalline)
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Snowflake Obsidian
Obsidian with Cristobalite inclusions (SiO2)
igneous
Granite
Felsic intrusive igneous rock
igneous
Quartz-rich pegmatite with mica and dark inclusions
Pegmatite; chiefly quartz (SiO₂), with feldspar and biotite/tourmaline inclusions
igneous
Likely weathered quartz-bearing rock fragment
Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite
mineral
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
fossil
Granite
Felsic intrusive igneous rock
igneous
Likely schist, possibly serpentinite
Mica schist; potential chlorite–serpentine-rich metamorphic rock
metamorphic
Fossil Shell (Bivalve)
Class Bivalvia (fossilized)
fossil
Schist
Schist (Metamorphic Rock)
metamorphic
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
metamorphic
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
mineral
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
metamorphic
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
mineral
Not a rock, mineral, or geological specimen
N/A
Marble
Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)
metamorphic
River Stone (likely Basalt or Greywacke)
Basalt with mineral veining
igneous