Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Category
Browse metamorphic or sedimentary specimens identified by the Rock Identifier community.
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Sapphirine in Magnesian Schist
Sapphirine: (Mg,Al)8(Al,Si)6O20
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
Apatite
Apatite Group (e.g., Fluorapatite Ca5(PO4)3F, Chlorapatite Ca5(PO4)3Cl, Hydroxylapatite Ca5(PO4)3(OH))
Rock Crystal Quartz
Quartz (SiO₂)
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Red Jasper
Jasper (Silicon Dioxide with Iron inclusions - SiO2)
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Green Aventurine
Silicon Dioxide (Quartz) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)
Muscovite Mica
Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2
Rhodonite
Manganese Inosilicate (MnSiO3), often with Ca, Fe, Mg, Zn
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Magnetite
Magnetite (Fe3O4)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite)
Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)
Calcite
Calcite
Calcite (CaCO3)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Dumortierite Quartz
Dumortierite (Al7BO3(SiO4)3O3 / inclusion in SiO2)
Emerald in Matrix (Quartz/Schist)
Beryl (Be₃Al₂Si₆O₁₈) with Chromium/Vanadium impurities
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Green Calcite
Calcite (CaCO3)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)
Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates
Ruby Fuchsite / Ruby in Fuchsite
Ruby (Al2O3 variety corundum) and Fuchsite (K(Al,Cr)2AlSi3O10(OH)2 - a chromium-rich variety of muscovite mica) in Quartz matrix
Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Green Aventurine
Silicon dioxide (SiO2) with inclusions of Fuchsite mica
Rhodonite
Manganese Silicate (Mn, Fe, Mg, Ca)SiO3
Quartz (likely Clear Quartz or Rock Crystal)
Quartz (SiO2)
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz on Chlorite Schist
Chlorite Schist (Mg,Fe)3(Si,Al)4O10(OH)2 with Quartz (SiO2)
Green Tourmaline
Elbaite (part of Tourmaline group), Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
Ruby in Zoisite
Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende
Fuchsite
Chromium-rich Muscovite (KAl2(AlSi3O10)(OH,F)2 with Cr replacements)
Jade
There are two distinct minerals commonly known as Jade: Nephrite (a calcium magnesium silicate - Ca2(Mg,Fe)5Si8O22(OH)2) and Jadeite (a sodium aluminum silicate - NaAlSi2O6). Based on the image showing a typically softer, more fibrous appearance, it is likely Nephrite.