Limonite with Quartz
FeO(OH)·nH2O (Limonite) with SiO2 (Quartz)
mineral
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
mineral
Limonite (Ironstone Concretion)
Limonite (Hydrous Ferric Oxides mixed with Goethite)
sedimentary
Diorite Gneiss
Foliated Diorite Gneiss
metamorphic
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions
igneous
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite
Granite (Alkali-feldspar, Quartz, and Plagioclase composition)
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Cat's Eye Moonstone (Feldspar)
Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8) inclusions
mineral
Dragon Blood Jasper
Quartz (SiO2) with Epidote and Piedmontite inclusions
sedimentary
Gossan with Copper Carbonate (Chrysocolla/Malachite)
Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)
Mineral/Sedimentary Interface
Gabbro
Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
igneous
Banded Gneiss (with Quartz Vein)
Gneiss (Metamorphic rock of varying mineralogy)
metamorphic
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2 with minor Fe2O3)
sedimentary
Hypersthene
Enstatite (Hypersthene variety), (Mg,Fe)SiO3
mineral
Mica Schist
Mica Schist (primarily Muscovite or Biotite)
metamorphic
Charoite
Charoite (K(Ca,Na)2Si4O10(OH,F)·nH2O)
metamorphic
Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
metamorphic
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
sedimentary and igneous (mixed)
Red Granite
Phaneritic Plutonic Rock (High Potassium Feldspar)
igneous
Granite
Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase)
igneous
Chert (Green River Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
mineral
Granite (Dioritic or Hornblende-rich)
Phaneritic Plutonic Felsic to Intermediate Igneous Rock
igneous
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
metamorphic
Granite
Intrusive Phaneritic Felsic Igneous Rock
igneous
Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Mineral
Hypersthene
(Mg,Fe)SiO3 - Enstatite-Ferrosilite series
mineral
Chert (specifically Silex or Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Drill Core Sample
Cylindrical Rock Core (Specific mineralogy varies by extraction site)
Metamorphic (Likely Gneiss or Schist based on texture)
Granite
Granite
igneous
Banded Gneiss
Gneiss (Metamorphic rock of variable mineralogy, often quartz-feldspar base)
metamorphic
Gneiss
Gneiss (a type of metamorphic rock)
Metamorphic Rock
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic