Anthropogenic Material (Man Made Rock)

Chalcedony (Banded/Mottled Variety)

Chalcedony (a cryptocrystalline variety of Quartz, SiO2)

Obsidian

Volcanic glass (SiO2)

igneous

Corundum (Pink Sapphire / Ruby)

Al2O3 (Aluminum Oxide)

Mineral, often found as detrital grains in sedimentary rocks

Banded Gneiss

Gneiss (pronounced 'nice')

metamorphic

Quartz

Quartz (SiO2 - Silicon Dioxide)

Chert or Flint (polished/water-worn)

Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.

Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)

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).

Milky Quartz with Hematite/Limonite staining

Silicon Dioxide (SiO2)

Turquoise (likely stabilized or simulated Howlite)

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

Diamond

Carbon (C)

Sapphire (likely blue synthetic sapphire or blue glass in a ring)

Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.

Turquoise (beads)

Turquoise; CuAl6(PO4)4(OH)8·4H2O

Quartz (River Pebble)

Quartz (SiO₂ - Silicon Dioxide)

Limestone

Calcium Carbonate (CaCO3)

Banded Chert

Microcrystalline Quartz (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Blue-dyed Quartz Druzy

Silicon Dioxide (SiO2) with artificial pigment

Limestone

Calcium Carbonate (CaCO3)

Obsidian

Volcanic Glass (Amorphous SiO2)

igneous

Chert (specifically White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Metamorphic rock (for both Nephrite and Jadeite)

Jade (Nephrite or Jadeite)

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2 - a variety of actinolite, an amphibole mineral); Jadeite (Na(Al,Fe3+)Si2O6 - a pyroxene mineral)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Mineral, specifically an iron ore

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)

Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement

Pyrite

Iron Sulfide (FeS2)

Black Jasper (Etched)

Silicon Dioxide (SiO2) with impurities

Pearl

Biogenic CaCO3 (Aragonite and Calcite)

Chert or Chalcedony

Microcrystalline Quartz (SiO2)

Chert (with Quartz)

Microcrystalline Quartz (SiO2)

Gabbro

Gabbro (Mg, Fe)2Si2O6 / (Ca, Na)(Al, Si)4O8

igneous

Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite

Limestone

Calcium Carbonate (CaCO3)