Organic Mineraloid And Mineral

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Greisen (Quartz-Muscovite-Turretine Rock)

Greisen

Fossilized Shark Teeth

Carcharhiniformes or Lamniformes species (common mineral: Fluorapatite/Ca5(PO4)3F)

Blue Lace Agate

Chalcedony (a form of Quartz) - SiO2

Sandstone

Sandstone (lithified sand)

Unidentifiable Rock Fragment

Sandstone (likely a river or beach pebble)

Sandstone (a clastic sedimentary rock)

Sandstone

Arenite (general term for sandstone)

Brachiopod Fossil (Spiriferid)

Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)

Veined Pebble (likely a Quartz-Veined Pebble)

Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)

Sandstone

Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)

Baroque Pearl (and potentially a small Sapphire/Blue Topaz)

Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.

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)

Banded Gneiss

Gneiss (variable mineral composition)

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Puddingstone

Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Orange Tabby (Felis catus)

Felis silvestris catus (variety: Red Mackerel Tabby)

Hand-Drawn Trading Card (Amateur Artwork)

Cellulose-based substrate with wax/graphite/ink deposit (n/a for minerals)

Golden Sheen Obsidian

Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen

Black Obsidian and Hematite

Volcanic Glass (SiO2) and Hematite (Fe2O3)

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Tiger's Eye and Carnelian Quartz

Silicon Dioxide (SiO2)

Obsidian and Phantom Quartz

Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)

Mixed Tumbled Gemstones and River Rocks

Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)

Red Coral

Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.

Crushed Stone (Gravel/Aggregates)

Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Pegmatite (Granitic)

Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)

Banded River Rock / Gneiss (highly weathered)

Gneiss

Pearl (likely Freshwater or Akoya Cultured)

Aragonite / Conchiolin composite (CaCO3)

Osumilite in Granite Matrix

(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30

Pegmatite (likely Granitic Pegmatite)

Pegmatite (a coarse-grained igneous rock, often with granitic composition)

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Granite

Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)

Schist (Diamond Drill Core)

Mica Schist

Gneiss

Gneiss (a type of metamorphic rock)

Limonite (Ironstone Concretion)

Limonite (Hydrous Ferric Oxides mixed with Goethite)

Schist

Mica Schist

Diorite

Diorite (Intermediate plutonic rock)

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions