Hematite
Hematite (Fe2O3)
Mineral
Category
Metamorphic Or Igneous Alteration
Browse metamorphic or igneous alteration specimens identified by the Rock Identifier community.
Rhodonite
Rhodonite (MnSiO3)
Mineral
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Mineral
Magnetic Hematite
Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)
Mineral
River Pebbles (Sandstone and Quartzite)
SiO2 (Quartz) dominated clastic rocks
sedimentary and metamorphic
Unakite
Epidote-Feldspar rock (specifically, a variety of granite)
Metamorphic rock
Basalt with Epidote/Chlorite
Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))
igneous
Basalt (with possible alteration or lichen)
Mafic volcanic rock (primarily Plagioclase and Pyroxene)
igneous
Stichtite in Serpentine (Atlantasite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
Metamorphic rock / Mineral variety
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)
Mineral
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Mineral
Serpentine
Serpentine group minerals (e.g., Antigorite, Chrysotile, Lizardite). Chemical formula: (Mg, Fe)₃Si₂O₅(OH)₄
Mineral, often found as a rock (metamorphic)
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Mineral
Blue Apatite
Apatite-(CaF), Ca5(PO4)3F (Calcium Fluorophosphate)
mineral
Magnetite / Hematite rich ore
Magnetite (Fe3O4) or Hematite (Fe2O3)
mineral
Magnetite
Magnetite (Fe3O4)
mineral
Quartz (Drusy/Crystalline)
Silicon Dioxide (SiO2)
mineral
Zoisite with Ruby (Anyolite)
Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)
metamorphic
Bornite
Bornite (Cu5FeS4)
mineral
Unakite
Epidote-Feldspar rock
Metamorphic Rock
Soapstone
Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)
Metamorphic Rock
Rutilated Quartz
SiO2 with TiO2 inclusions (Rutile)
Mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Mineral
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
mineral
Blue Apatite
Apatite, Ca5(PO4)3(F,Cl,OH)
mineral
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
mineral
Amazonite (likely mixed with other feldspars/minerals)
Amazonite is a variety of Microcline, which is a tectosilicate mineral, formula KAISi3O8. The mixed beads could include other feldspars or quartz.
Mineral
Magnetite
Iron(II,III) oxide (Fe3O4)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Rhodonite, Gray Moonstone, and White Feldspar Mix
Multiple: MnSiO3 (Rhodonite), (K,Na)AlSi3O8 (Feldspar/Moonstone)
mineral
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
mineral
Milky Quartz
Quartz (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Garnet
Almandine-Pyrope group, X3Y2(SiO4)3
mineral
Magnetite-rich Iron Ore
Magnetite (Fe3O4)
mineral
Ruby (Corundum)
Aluminum oxide (Al2O3) with Chromium traces
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is cryptocrystalline quartz). Chemical Formula: SiO2 with inclusions of crocidolite fibers.
Mineral
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral