Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Category
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Silver (Native Element)
Ag (Argentum)
Orange Calcite
Calcite (Calcium Carbonate - CaCO3)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Volcanic glass (high silica volcanic rock)
Dendritic Opal
Opalized Chalcedony with Manganese Inclusions (SiO2 · nH2O)
Obsidian
Amorphous volcanic glass (SiO2)
Obsidian
Volcanic Glass (SiO2)
Peridot
Olivine (Mg, Fe)2SiO4
Obsidian
Obsidian (Volcanic Glass)
Milky Quartz with Dendritic Inclusions
Silicon Dioxide (SiO2)
Obsidian
Amorphous Volcanic Glass (primarily SiO2)
Obsidian
Volcanic glass (SiO2-rich amorphous silicate)
Quartz
Silicon Dioxide (SiO2)
Tiffany Stone
Bertrandite Fluorite (CaF2 + Be4Si2O7(OH)2)
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Dendritic Agate (River Pebble)
Silicon Dioxide (SiO2) with Manganese or Iron oxide inclusions
Quartzite
Meta-quartzite (SiO2)
Obsidian
Volcanic Glass (predominantly SiO2)
Dendritic Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
Obsidian
Volcanic Glass (SiO2 rich)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Obsidian
Volcanic Glass (70% or more SiO2)
Ironstone Concretion / Goethite-Hematite Nodule
Goethite/Hematite (α-FeO(OH) / Fe2O3)
Sandstone (likely Quartzose Sandstone)
Arenite
Not a rock, mineral, or geological specimen
Obsidian
Obsidian (Volcanic Glass, SiO2)
Quartzite River Rock with Dendrites
Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Quartzite Pebble (Yellow/Cloudy Quartz)
Silicon Dioxide (SiO2) - Recrystallized Sandstone