Mineral In A Matrix (Likely Quartz Or Feldspar)

Chinese Writing Stone

Porphyritic Basalt or Porphyritic Andesite

Ferruginous Sandstone (Gozzanous)

SiO2 (Quartz) with FeO(OH) (Goethite) or Fe2O3 (Hematite) coating

Chalcedony Nodule (Agate/Chert)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Gneiss (specifically Banded Gneiss)

Gneiss

Ocean Jasper

Spherulitic Chalcedony (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Yellow Quartz (Citrine/Yellow Chalcedony)

Silicon Dioxide (SiO2)

Granite

Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)

Pink Granite

Phaneritic Quartz-Feldspar Plutonic Rock

Granite

Phaneritic Felsic Intrusive Igneous Rock

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

Granite

Granite (Felsic Plutonic Rock)

Amethyst (Rough Quartz)

Silicon Dioxide (SiO2) with iron impurities

Sphalerite in Matrix (Polished Point)

Zinc sulfide (Zn,Fe)S

Pegmatite with Muscovite

Granitic Pegmatite (KAl2(AlSi3O10)(OH)2)

Gneiss (Metamorphic Cobble)

Gneiss

Granite

Granite (Phaneritic intrusive igneous rock)

Basalt with Quartz Veins

Basalt (SiO2 range 45-52%)

Granite

Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8), and Mica)

Yellow Quartzite (River Pebble)

Quartzite (mainly SiO2)

Red Quartzite / Ferruginous Sandstone

Quartzite (SiO2 with iron oxide impurities)

Quartzite

Quartzite (SiO2)

Fossiliferous Sedimentary Rock (Coquina/Limestone)

Fossiliferous Calcarenite / Bioclastic Limestone

Quartz (Tumbled)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Red Sandstone

Arenite (Ferruginous Sandstone)

Gneiss

Gneiss (High-grade metamorphic rock)

Porphyry

Porphyritic Basalt or Porphyritic Andesite

Quartz Pebble

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Granite

Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)

Chalcedony in Matrix

Silicon Dioxide (SiO2)

Quartz (Pink/Orange Variety)

Silicon Dioxide (SiO2)

Green Aventurine (Fuchsite-bearing Quartz)

Silicon Dioxide with Chromium-rich Muscovite (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Muscovite (Mica) in Quartz Matrix

Muscovite (KAl2(AlSi3O10)(OH)2) and Quartz (SiO2)

Granite

Granite (Felsic Plutonic Rock / SiO2 + Al2O3 + K2O + Na2O + CaO + FeO + MgO)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Feldspar

Potassium Feldspar (KAlSi3O8)

Quartz with Mica inclusions (likely Schist or Gneiss host)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Emerald In Matrix (Quartz/Calcite)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities