Metamorphic (Man Made)

Diamond (in a jewelry setting)

Cubic Carbon (C)

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Serpentine Jade (New Jade/Olive Jade)

Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

Basalt

Basalt (Mafic volcanic rock)

Pearl

Calcium Carbonate (CaCO3) with Conchiolin

Amazonite

KAlSi3O8 (Potassium Feldspar, variety of Microcline)

Diamond

Carbon (C)

Scoria

Scoria (a vesicular basalt or andesite)

Rough Diamond

Pure Carbon (C)

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Pearl

Aragonite (CaCO3 with conchiolin)

Orange Calcite

Calcite (CaCO3)

Amethyst

SiO2 (Silicon Dioxide) - a variety of Quartz

Granite (with Almandine Garnet inclusions)

Granite composed primarily of Quartz (SiO2), K-Feldspar (KAlSi3O8), and Almandine Garnet (Fe3Al2(SiO4)3)

Nacre (Mother of Pearl)

Nacre (Biogenic Aragonite/Calcite composite, CaCO3)

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Calcite

Calcite (CaCO3)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Chert (specifically White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diamond (Cluster Ring)

Carbon (C)

Granite (Pegmatitic)

Phaneritic Felsic Igneous Rock

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Rough Diamond

Diamond (pure Carbon, C)

Diamond

Carbon (C)

Quartz

Silicon Dioxide (SiO2)

Ruby

Corundum (Al₂O₃) with Chromium (Cr)

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Chert (and Jasper/Chalcedony mixture)

Microcrystalline Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Rough Diamond

Diamond (pure Carbon, C)

Sandstone (likely Quartzose Sandstone)

Arenite

Sandstone

Arenite

Chalk

Micrite (primarily Calcium Carbonate, CaCO3)

Diamond (in jewelry setting)

Carbon (C)

Pearl

Aragonite (CaCO3) with Conchiolin

Granite

Granite (a felsic intrusive igneous rock)

Nephrite Jade

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

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Quartz (Milky Quartz)

Quartz (SiO2 - Silicon Dioxide)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.