Rock Identifier

Category

Metamorphic Or Igneous Alteration

Browse metamorphic or igneous alteration specimens identified by the Rock Identifier community.

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Gneiss (specifically a granitic gneiss cobble) (Gneiss (high-grade regional metamorphic rock)) — metamorphic

Gneiss (specifically a granitic gneiss cobble)

Gneiss (high-grade regional metamorphic rock)

River Cobble (Gneiss/Migmatite) (Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)) — metamorphic

River Cobble (Gneiss/Migmatite)

Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)

Black Tourmaline (Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)) — Mineral

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Black Star Diopside (Diopside (CaMgSi2O6) with asterism) — Mineral

Black Star Diopside

Diopside (CaMgSi2O6) with asterism

Apatite (Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))) — mineral

Apatite

Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))

Gneiss (Metamorphic Rock) (Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)) — metamorphic

Gneiss (Metamorphic Rock)

Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)

Quartzite (Quartzite) — Metamorphic

Quartzite

Quartzite

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Greenstone (Epidote/Chlorite-rich Metabasalt) (Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))) — metamorphic

Greenstone (Epidote/Chlorite-rich Metabasalt)

Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

Banded Gneiss (Gneiss (High-grade Metamorphic Rock)) — metamorphic

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Rough Dark Green Sapphire (Corundum (Al2O3)) — mineral

Rough Dark Green Sapphire

Corundum (Al2O3)

Quartz Pebble (Quartz (Silicon Dioxide, SiO2)) — mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (specifically Citrine or Yellow Quartzite pebble) (Silicon Dioxide (SiO2)) — mineral

Quartz (specifically Citrine or Yellow Quartzite pebble)

Silicon Dioxide (SiO2)

Black Tourmaline (Schorl) (Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)) — Mineral

Black Tourmaline (Schorl)

Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)

Grey Agate (Banded Chalcedony) (Agate (Silicon Dioxide - SiO2)) — mineral

Grey Agate (Banded Chalcedony)

Agate (Silicon Dioxide - SiO2)

Tumbled Moonstone and Amazonite Chips (Orthoclase (KAlSi3O8) and Microcline (KAlSi3O8) of the Feldspar Group) — mineral

Tumbled Moonstone and Amazonite Chips

Orthoclase (KAlSi3O8) and Microcline (KAlSi3O8) of the Feldspar Group

Milky Quartz (Quartz (Silica / Silicon Dioxide), SiO2) — mineral

Milky Quartz

Quartz (Silica / Silicon Dioxide), SiO2

Milky Quartz (Quartz (Silica / Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silica / Silicon Dioxide, SiO2)

Clear Quartz (Tumbled) (Quartz (Silicon Dioxide - SiO2)) — mineral

Clear Quartz (Tumbled)

Quartz (Silicon Dioxide - SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Citrine Quartz (Citrine (Silicon Dioxide, SiO2)) — mineral

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Citrine Geode Fragment (Citrine (Silicon Dioxide with Iron Impurities), SiO2) — mineral

Citrine Geode Fragment

Citrine (Silicon Dioxide with Iron Impurities), SiO2

Yellow Quartz (Citrine Quartz Pebble) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Quartz (specifically Milky/Gray Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (specifically Milky/Gray Quartz)

Silicon Dioxide (SiO2)

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)

Milky Quartz (Silicon dioxide (SiO2)) — mineral

Milky Quartz

Silicon dioxide (SiO2)

Amazonite (Amazon Stone) (Tectosilicate Microcline (KAlSi3O8)) — mineral

Amazonite (Amazon Stone)

Tectosilicate Microcline (KAlSi3O8)

Amethyst (Amethyst (Silicon Dioxide with iron impurities, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Amethyst (SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz) — mineral

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Citrine Quartz (Silicon Dioxide (SiO2)) — mineral

Citrine Quartz

Silicon Dioxide (SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Amethyst (Amethyst (Silicon Dioxide - SiO2 with iron impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Prehnite (Prehnite Ca2Al2Si3O10(OH)2) — mineral

Prehnite

Prehnite Ca2Al2Si3O10(OH)2

Quartz (Milky/Common) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Milky Quartz (Quartz (Silicon Dioxide, SiO2)) — Mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)