Mineral In A Matrix (Likely Quartz Or Feldspar)

Weathered basalt with quartz or calcite veining

Basalt (fine-grained mafic volcanic rock), locally altered and vein-filled

Sandstone (with vugs or solution cavities)

Arenite (primarily Quartz and Feldspar with CaCO3 or SiO2 cement)

Unakite (likely)

Epidote–K-feldspar–quartz aggregate; epidote: Ca₂(Al,Fe³⁺)₃Si₃O₁₂(OH)

Weathered polymictic gravel/conglomeratic rock

Polymictic conglomerate or poorly lithified alluvial gravel; chiefly quartz, feldspar, mica, and dark lithic fragments

Quartz with Matrix

Silicon Dioxide (SiO2)

Red porphyritic volcanic rock, likely rhyolite or andesite

Porphyritic rhyolite/andesite; composition appears quartz–feldspar with iron-oxide staining

Blue-green tourmaline (likely indicolite)

Elbaite tourmaline, Na(Li1.5Al1.5)Al6(BO3)3Si6O18(OH)4

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

Quartz-bearing pegmatite, possibly with mica

Granitic pegmatite; chiefly quartz (SiO₂) and feldspar, with probable mica and dark accessory minerals

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

Conglomerate pebble

Polymictic conglomerate (clast-supported)

Conglomerate (polymictic, possibly metamorphosed)

Polymictic conglomerate; clasts cemented in a dark, likely quartz-rich matrix

Vesicular basalt with pink mineral inclusions

Basalt, likely porphyritic/vesicular basalt; inclusions may be calcite, zeolite, or weathered feldspar

Greenschist

Greenschist (Chlorite Schist facies)

Amazonite

Potassium Feldspar (Microcline) - K(AlSi3O8)

Porphyritic Basalt

Aphanitic-Porphyritic Basalt

Weathered, iron-stained feldspathic rock (probable granite or granitic pegmatite)

Quartz–feldspar granitoid; visible blue grains may be altered feldspar or accessory minerals

Graphic Granite

Graphic Pegmatite

Orbicular Jasper (Ocean Jasper tendency)

Silicon Dioxide (SiO2) with impurities

Copper-bearing quartz/rock fragment with attached mica

Chalcopyrite-bearing quartz or altered igneous rock; attached flake likely muscovite or biotite mica

Rhyolite

Rhyolite

Pegmatitic mica-quartz-feldspar specimen

Granitic pegmatite, chiefly quartz (SiO₂), feldspar, and muscovite/biotite mica

Sandstone (Quartzose Pebble)

Clastic Sedimentary Rock (Litharenite/Quartz arenite)

Unidentified weathered rock, possibly quartz-bearing granite or rhyolite

Indeterminate; likely quartz–feldspar-rich silicate rock

Mica-rich granite or granitic pegmatite

Biotite granite; primarily quartz, feldspar, and biotite mica

Likely gneiss

Quartz–feldspar–mica gneiss (exact identification requires closer examination)

Quartz vein rock, likely iron-stained quartzite or hydrothermal quartz

Mostly quartz (SiO₂), with iron oxides and minor feldspar or mica

Quartz-bearing rock fragment

Likely quartz (SiO₂) with iron-oxide staining and possible feldspar/matrix minerals

Aquamarine on Feldspar Matrix

Beryl (Be3Al2Si6O18) with Potassium Feldspar (KAlSi3O8)

Pegmatite with quartz, feldspar, mica, and tourmaline

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, muscovite, and black schorl tourmaline (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Gneiss with Quartz Vein

Metamorphic Gneiss

Weathered quartz-rich pebble

Milky quartz, chiefly silicon dioxide (SiO₂), possibly with iron-oxide staining and minor feldspar

Conglomerate (or Breccia / Porphyry)

Clastic Sedimentary Rock (Conglomerate / Sandstone)

Dark mafic rock, likely altered basalt or gabbro

Fine- to medium-grained mafic silicate rock; probable basaltic composition with plagioclase and pyroxene, possibly chloritized/serpentinized

Garnet in Matrix (likely Almandine in Quartz/Mica Schist)

Almandine Garnet (Fe3Al2(SiO4)3) in Quartz-Feldspar host rock

Polished banded stone, likely black marble or banded gneiss

Graphitic banded marble or quartz-feldspar biotite gneiss; exact identification requires testing

Quartz-rich metamorphic rock, likely quartzite or quartz-veined schist

Quartz (SiO₂) with mica/chlorite-rich schistose matrix; possibly minor feldspar and sulfides

Banded gneiss

Quartz–feldspar gneiss, possibly biotite-bearing; exact identification requires testing

Quartz with Mica/Host Rock

Silicon Dioxide (SiO2) with Phyllosilicates

Weathered mica-rich pegmatite

Granitic pegmatite composed chiefly of quartz, feldspar, and mica (likely biotite/muscovite)

Banded quartz-rich rock (possibly pegmatite)

Likely quartz–feldspar pegmatite; identification is tentative from the photo

Granite

Granite: coarse-grained intrusive rock composed mainly of quartz, feldspar, and mica