Mineral, Part Of A Rock

Granite Water-Worn Pebble

Phaneritic intrusive igneous rock (Quartz, Feldspar, Mica)

Quartzite

Quartzite (containing SiO2)

Tooth or bone fragment (likely animal tooth)

Indeterminate vertebrate tooth; possibly a small mammal or fish tooth

Milky Quartz

Silicon Dioxide (SiO2)

River Pebble (Quartzite/Sandstone mix)

Quartzite (primarily SiO2)

Weathered quartz-rich metamorphic rock (likely gneiss or quartzite)

Quartz (SiO₂) with probable feldspar, mica, and iron-oxide alteration

Milky Quartz

Silicon Dioxide (SiO2)

Vesicular basalt (likely scoria)

Basaltic volcanic rock; mainly plagioclase, pyroxene, and olivine with gas vesicles

Weathered quartzite pebble

Quartzite, composed predominantly of quartz (SiO₂)

Quartz-rich conglomeratic sandstone

Lithic arkose/conglomerate, dominated by quartz and feldspar grains

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Serpentine (Healerite variety)

Serpentine group, Mg3Si2O5(OH)4

Granite (Orthoclase rich)

Granite (composed primarily of Quartz and Potassium Feldspar KAlSi3O8)

Ruby (set in a ring; possibly synthetic or imitation)

Corundum, Al₂O₃; red color is typically caused by chromium

Basalt (with possible weathered crust)

Basalt (composition: Plagioclase feldspar, Pyroxene, Olivine)

Basalt (Vesicular/Waterworn)

Basalt (Mafic Extrusive Igneous Rock)

Glauconitic Sandstone (Greensand)

Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Quartz (likely milky/gray variety)

Quartz (SiO₂)

Quartz (Water-worn pebble)

Silicon Dioxide (SiO2)

Serpentine

Antigorite, Lizardite, or Chrysotile; (Mg,Fe)3Si2O5(OH)4

Weathered granite pebble

Granite; chiefly quartz, potassium feldspar, plagioclase, and minor biotite/hornblende

Rounded granite or granitic pebble

Granite; mainly quartz, feldspar, and mica (exact identification is uncertain from the photograph)

Lepidolite (likely)

K(Li,Al)3(Al,Si)4O10(F,OH)2 (Phyllosilicate mineral, part of the mica group)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble (Citrine or Iron-Stained)

Silicon Dioxide (SiO2)

Granite pebble

Granite; chiefly quartz, feldspar, and mica (variable composition)

Small rounded stone, likely quartz-rich granite or granitic rock

Probable granitoid fragment; mainly quartz (SiO₂) and feldspar, with minor dark mica/amphibole

Scoria (Lava Rock)

Scoria

Quartz Pebble

Silicon Dioxide (SiO2)

Siltstone

Siltstone (primarily composed of SiO2 with various clay minerals)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Red vesicular basalt (tumbled volcanic rock)

Vesicular basalt; predominantly plagioclase, pyroxene, and iron-rich olivine

Yellow calcite crystal

Calcite (CaCO₃), likely honey/yellow calcite

Basalt (River Stone)

Basalt (Extrusive Igneous Rock)

Milky chalcedony cabochon ring

Chalcedony, microcrystalline quartz (SiO₂), likely white or pale agate variety

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)

Rounded dark pebble, likely basalt or fine-grained volcanic rock

Basalt (probable; composition dominated by plagioclase and pyroxene, with possible olivine)