Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Category
Browse mineral, often found in sedimentary deposits specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
Banded Calcite (Tumbled)
Calcium Carbonate (CaCO3)
Red Vanadinite on Matrix
Vanadinite (Pb5(VO4)3Cl)
Ruby (Corundum)
Corundum (Aluminum Oxide) with chromium trace elements, Al2O3
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Chert Nodule (River Cobble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Turquoise in Matrix
Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)
Amygdaloidal Basalt with Quartz/Calcite Inclusions
Amygdaloidal Basalt (SiO2 / CaCO3 inclusions)
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
Conglomerate
Conglomerative Sedimentary Rock
Quartzite River Rock
Quartzite (primarily SiO2)
Greenstone (Greenschist)
Greenschist (composed of Chlorite, Epidote, and Actinolite)
Chert / Flint
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Ferruginous Conglomerate
Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))
Gold Nugget
Native Gold (Au)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Red Jasper
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Malachite
Malachite - Cu2CO3(OH)2
Milky Quartz
Silicon Dioxide (SiO2)
Carnelian
SiO2 (Microcrystalline Quartz / Chalcedony)
Yellow Jasper
Silicon Dioxide (SiO2) with impure Iron inclusions
Amygdaloidal Basalt
Amygdaloidal Basalt with Secondary Infilling (e.g., Agate, Quartz, or Zeolite)
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst Geode
Silicon Dioxide with trace inclusions of Iron (SiO2)
Fluorite (Rainbow/Purple Fluorite)
Calcium Fluoride (CaF2)
Sandstone Cobble
Clastic Sedimentary (Sandstone)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Glauconitic Sandstone
Glauconitic Sandstone with high Glauconite concentration ((K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Yellow or Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Aragonite (Sputnik habit)
Aragonite (Calcium Carbonate, CaCO3)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Black Chert)
Silicon Dioxide (SiO2)
Rough Diamond
Diamond (C)