Sedimentary Or Igneous

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Milky Quartz

Quartz (SiO2)

Mica Group Minerals

There isn't a single scientific name as 'Mica' refers to a group of phyllosilicate minerals. Common scientific names include Muscovite (KAl₂ (AlSi₃O₁₀)(OH)₂), Biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH)₂), Phlogopite (KMg₃AlSi₃O₁₀(OH)₂), and Lepidolite (K(Li,Al)₃(Al,Si,Rb)₄O₁₀(F,OH)₂).

River Pebbles and Quartz

Mixed Igneous, Sedimentary, and Metamorphic Rocks (Silicon Dioxide SiO2 dominant)

Graphite

Graphite (Carbon, C)

Pink Opal / Peruvian Opal

Hydrated amorphous silicon dioxide (SiO2·nH2O)

Biotite Mica

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

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Apatite

Apatite Group (e.g., Fluorapatite Ca5(PO4)3F, Chlorapatite Ca5(PO4)3Cl, Hydroxylapatite Ca5(PO4)3(OH))

Rock Crystal Quartz

Quartz (SiO₂)

Nephrite Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)

Gneiss (specifically a Banded Gneiss pebble)

Gneiss (High-grade Regional Metamorphic Rock)

River Cobble (likely Basalt or Chert)

Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous

Crystal Quartz Beads (likely Clear Quartz)

Quartz (SiO₂)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Fluorite in Matrix

Fluorite (CaF2) within a host rock matrix

Gneiss

Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Sandstone or Siltstone

Arenite (if sandstone)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Laterite

Laterite (no specific mineral formula as it's a rock type)

Muscovite Mica

Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2

Quartz (River Pebble)

Quartz (SiO₂ - Silicon Dioxide)

Obsidian and Green Calcite

Volcanic Glass and Calcium Carbonate (CaCO3)

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Green Calcite

Calcite (CaCO3)

Gneiss

Gneiss (High-grade regional metamorphic rock)

White Topaz

Al2SiO4(F,OH)2

Magnetite

Magnetite (Fe3O4)

Calcite

Calcite (CaCO3)

Quartz

Silicon Dioxide (SiO2)

Granite

Granite

Peridot and Citrine Gemstones (in a ring setting)

Peridot (Olivine: (Mg,Fe)2SiO4), Citrine (Quartz: SiO2)

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)

Quartz (likely milky/gray variety)

Quartz (SiO₂)

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Muscovite Mica

Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Clear Quartz (Rock Crystal)

Quartz (SiO₂)

Quartz

Silicon Dioxide (SiO2)

Pumice

Pumice (volcanic rock)

Jasper in Basalt Matrix

Silicon Dioxide (SiO2) with impurities; Chalcedony