Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Conglomerate
Conglomerate (SiO2 primary clasts with lithic matrix)
Sandstone
Arenite (primarily SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
Celestine (or Celestite) Geode
Strontium Sulfate (SrSO4)
Granite
Granite (Felsic Plutonic Rock)
Amethyst
Amethyst (variety of Quartz, SiO2)
Malachite
Copper(II) carbonate hydroxide [Cu2CO3(OH)2]
Granite
Granite (Felsic Plutonic Rock)
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Pink Granite
Granite (Alkali-feldspar granite)
Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)
Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)
Red Quartzite / Ferruginous Sandstone
Quartzite (SiO2 with iron oxide impurities)
Sapphirine in Magnesian Schist
Sapphirine: (Mg,Al)8(Al,Si)6O20
Amazonite (or Amazon Stone)
Potassium Feldspar (Microcline), K(AlSi3O8)
Granite
Granite (Phaneritic Quartz-Feldspar rock)
Gold Nugget
Native Gold (Au)
Ironstone Concretion (Moqui Marble)
Iron-oxide Concretion (Hydrated ferric oxide, Fe2O3·nH2O)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
Fuchsite Quartzite (Green Quartzite)
Fuchsite-bearing Quartzite (K(Al,Cr)2(AlSi3O10)(OH)2 + SiO2)
Sandstone (Iron-stained)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Sandstone (with Lichen)
Arenite (primarily SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Prehnite
Prehnite, Ca2Al2Si3O10(OH)2
Conglomerate
Conglomerate (SiO2 matrix with various inclusions)
Sandstone
Arenite (SiO2 principal)
Ferruginous Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Chert (Flint)
Chert (SiO2)
Rhyolite
Rhyolite (felsic extrusive igneous rock)
Agate
Silicon Dioxide (SiO2)
Rose Quartz
Quartz (SiO₂), specifically a variety of Quartz
Dendritic Agate or Tree Agate
Silicon Dioxide (SiO2) with impurities of manganese or iron oxide
Garden Quartz
Silicon Dioxide (SiO2) with various inclusions
Quartz (Quartzite Pebble)
Silicon Dioxide (SiO2)
Basalt
Basalt
Chert (Cherty Limestone / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite (Beach Pebble)
Quartzite (SiO2)