Mineral (Silicate Variety)

Labradorite (likely Black Labradorite or Larvikite)

Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.

Rose Quartz

Rose Quartz (SiO2)

Obsidian

Obsidian (principally SiO2 silicon dioxide)

Serpentine

Serpentinite (composed mainly of Group Minerals Antigorite, Chrysotile, and Lizardite; Mg3Si2O5(OH)4)

Obsidian

Volcanic glass (mainly SiO2 with inclusions)

Obsidian

Volcanic glass (SiO2 - Silicon dioxide predominant composition)

Schist

Schist

Obsidian

Obsidian (Volcanic Glass; SiO2 content > 70%)

Popcorn

Zea mays everta (P. Wilson) (Botanical name for the corn variety)

Kyanite (Blue and Green varieties)

Kyanite (Al₂SiO₅)

Stichtite in Serpentine (Atlantasite)

Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Tiger's Eye

Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)

Calcite

Calcite (CaCO3)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Bloodstone / Heliotrope

Silicon dioxide (SiO2) with inclusions

Garnet Schist

Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)

Strawberry Quartz

Quartz (SiO₂) with Goethite (α-FeO(OH)) and/or Lepidocrocite (γ-FeO(OH)) inclusions

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Druzy Quartz

Quartz (Silicon Dioxide, SiO2)

Pyrite

Pyrite (Iron Disulfide), FeS2

Rhodonite

Rhodonite (MnSiO3)

Obsidian

Obsidian (principally SiO2)

Rutilated Quartz

SiO2 with TiO2 inclusions

Gneiss

Gneiss (a metamorphic rock)

Red Jasper (beads)

Silicon Dioxide (SiO2) with iron inclusions

Obsidian

Volcanic Glass (comprised primarily of SiO2)

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

Schist (specifically Chlorite/Greenschist)

Chlorite Schist

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Rough Quartz (likely Rose or Amethyst variety)

Silicon Dioxide (SiO2)

Druzy Quartz Geode (Oco or Moroccan variety)

Silicon Dioxide (SiO2)

Chalcedony (specifically Agate or Common Opal variety)

Cryptocrystalline Silica (SiO2)

Quartz Crystal (specifically a Double-Terminated variety)

Silicon Dioxide (SiO2) - Low Quartz

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

Kyanite (Green and Blue varieties)

Kyanite (Al2SiO5)

Obsidian

Volcanic Glass (Amorphous Silica)

Shale

Shale (clastic sedimentary rock)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Agate (various color varieties)

SiO₂ (Silicon Dioxide)