Mineral With Metamorphic Or Sedimentary Host

Quartz-bearing altered rock

Likely quartz vein in weathered schist or gneiss; quartz is SiO₂

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly with chalcopyrite and weathered sulfides

Quartz-rich mineral fragment

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Milky quartz vein fragment

Quartz (silicon dioxide, SiO₂), massive or granular variety

Quartz-veined metamorphic cobble

Likely quartzite or quartz-rich metasedimentary rock; veins predominantly quartz (SiO₂)

Quartz vein in dark host rock

Milky quartz (SiO₂) in an unidentified dark metamorphic host, possibly amphibolite or schist

Blue Dumortierite Quartz

Dumortierite Inclusions in Quartz (SiO2 with Al7(BO3)(SiO4)3O3)

Pyrite-bearing metamorphic rock (probable pyrite schist or sulfide ore)

Pyrite (FeS₂) in a foliated, quartz–mica-rich host rock; exact identification requires testing

Weathered metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly in a quartz–iron-oxide host

Quartz Vein in Amphibolite / Gneiss

Quartz (SiO2) in Mafic Metamorphic Host Rock

Rough Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

Quartz vein fragment

Quartz (SiO₂), likely milky quartz with iron-oxide staining

Milky Quartz

Silicon Dioxide (SiO2)

Milky quartz–rich rock

Quartz (SiO₂), likely massive milky quartz with minor dark inclusions

Milky Quartz

Silicon Dioxide (SiO2)

Quartz-bearing metamorphic rock (likely quartz vein in schist or altered granite)

Quartz (SiO₂) in a mica-rich host rock; exact identification requires testing

Labradorite (a variety of Feldspar)

Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)

Metallic sulfide mineral fragment, likely galena

Galena (lead sulfide, PbS), tentative identification

Gneiss with Quartz Vein

Gneiss containing Quartz (SiO2) filler

Large calcite crystal cluster

Calcite (calcium carbonate, CaCO₃)

Quartz-veined Metamorphic Rock

Quartz-veined Schist or Gneiss

Metallic sulfide-rich rock, possibly pyrite-bearing schist or marcasite specimen

Likely pyrite (FeS₂) in a foliated host rock; exact identification requires testing

Likely blue-green kyanite

Kyanite, Al₂SiO₅

White quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite, a metamorphosed quartz sandstone

Quartz-Veined Gneiss or Metamorphic Rock with Quartz Veins

Quartz-veined metamorphic rock (Silicate mineral assemblage)

Quartz (Pebble)

Silicon Dioxide (SiO2)

Weathered sulfide-bearing metamorphic rock (probable pyrite schist)

Quartz–mica schist with iron sulfides, chiefly pyrite (FeS₂), possibly chalcopyrite (CuFeS₂)

Rough blue calcite

Calcite (CaCO₃), likely blue calcite

Tumbled honey calcite

Calcite (calcium carbonate, CaCO₃)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Pyrite-bearing rock (iron pyrite)

Pyrite, FeS₂, likely disseminated or massive in a host rock

Milky quartz / quartz vein fragment

Quartz, silicon dioxide (SiO₂)

Quartz Vein in Basalt or Sedimentary Host Rock

Silica-veined lithic fragment (SiO2 in host matrix)

Iron-oxide-stained rock, likely limonite/goethite-bearing stone

Limonite (a mixture of hydrated iron oxides, commonly including goethite, FeO(OH)) coating or staining a host rock

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Pyrite-bearing metamorphic rock (likely schist or gneiss)

Pyrite (FeS₂) in a quartz–mica-rich host rock

Cannonball Concretion

Calcite-cemented Sandstone Concretion

Pyrite-bearing metamorphic rock (likely pyrite schist or quartz–pyrite ore)

Pyrite (FeS₂) in a quartz–mica-rich matrix; exact host rock is uncertain from the image

Garnet Schist

Almandine Garnet in Mica Schist

Quartz Geode (River Cobble)

Silicon Dioxide (SiO2)

Schist (specifically Mica Schist)

Mica Schist (primarily composed of Muscovite KAl2(AlSi3O10)(OH)2 and Biotite)

Blue Apatite

Calcium Fluorophosphate (Ca5(PO4)3F)