Organic (Often Found By Beachcombers)

Quartz

Silicon dioxide (SiO2)

Malachite

Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)

Ferrocoke or Slag

Anthropogenic pyrometallurgical residue

Sandstone

Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Ironstone Concretion (Moqui Marble variety)

Ferruginous Sandstone Concretion

Carnelian Agate (with Quartz/Chalcedony)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Nodule)

Silicon Dioxide (SiO2)

Banded Calcite (often marketed as Mexican Onyx or Onyx Marble)

Calcite (Calcium Carbonate, CaCO3)

Ocean Jasper

Orbicular Jasper (Silicon Dioxide with impurities like Hematite and Chlorite, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Quartzite with Hematite

Silica (SiO2) with Ferric Oxide (Fe2O3) inclusions

Granodiorite

Granodiorite (phaneritic intrusive igneous rock)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Quartzite

Quartzite (SiO2)

Conglomerate

Conglomeratic Sandstone

Quartzite Pebble

Quartzite (primarily SiO2)

Concretion with Quartz Veining

Septarian Concretion (CaCO3 / SiO2)

Calcite

Calcium Carbonate (CaCO3)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Galena

Lead Sulfide (PbS)

White Topaz

Al2SiO4(F,OH)2

Azurite Malachite (Mixed)

Azurite-Malachite; Azurite: Cu3(CO3)2(OH)2 / Malachite: Cu2CO3(OH)2

Chert (including varieties like Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Granodiorite

Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)

Quartzite

Quartzite (SiO2)

Olivine (often within Peridotite)

Magnesium iron silicate, (Mg,Fe)2SiO4

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Pink Tourmaline (Rubellite)

Elbaite - Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3OH

Sedimentary Sandstone (Sandstone Slab)

Arenite (SiO2 with Fe2O3 staining)

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Banded Iron Formation (BIF)

Banded Iron Formation

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

Chert (Flint)

Microcrystalline Quartz (SiO2)

Sunstone

Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8

Yellow Quartzite

Quartzite (primarily SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)

Honey Calcite

Calcium Carbonate (CaCO3)

Quartzite (Iron-stained)

Quartzite (mostly SiO2)

Basalt

Mafic volcanic rock (Basalt)