Mineraloid (Anthropogenic)

Tiger's Eye (with Hematite/Jasper)

SiO2 (Silicon Dioxide) with Fe2O3 (Hematite)

Chert or flint nodule

Microcrystalline quartz (SiO₂), commonly chalcedony with possible opaline silica

Brick

Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)

Porphyritic Rhyolite or Andesite (Porphyry)

Porphyritic igneous rock (Composition depends on exact mineralogy, often Rhyolite or Andesite)

Gabbro

Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)

Gneiss

Gneiss (a type of metamorphic rock)

Dragon Blood Jasper

Microcrystalline Quartz (Chalcedony) with Epidote and Piemontite

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions

Jasper and Greenstone Pebble

Siliceous rock / Metamorphic pebble

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Hypersthene

Enstatite (Hypersthene variety), (Mg,Fe)SiO3

Charoite

Charoite (K(Ca,Na)2Si4O10(OH,F)·nH2O)

Serpentinite (probable)

Serpentinite, dominated by serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with dark magnetite or chromite and pale carbonate/talc possible

Dragon Blood Jasper

Quartz (SiO2) with Epidote and Piedmontite inclusions

Polished pale stone, likely limestone or quartzite pebble

Most consistent with micritic limestone (calcite, CaCO₃), though the image cannot confirm mineralogy

Sandstone

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

Prasiolite and Quartz Crystal Cluster

Quartz (SiO2); Prasiolite is a variety of Quartz

Tumbled sodalite (probable)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly blue-dyed jasper or lapis lazuli

Tumbled gray stone, likely serpentinite or weathered basalt

Tentatively serpentinite (predominantly serpentine-group minerals); identification is uncertain from the photograph

Chert (Green River Chert)

Microcrystalline Quartz (SiO2)

Polished orbicular granite (likely K2-type granite)

Granite, chiefly quartz, alkali feldspar, plagioclase, and dark amphibole/biotite; possible epidote-rich orbicules

Pegmatite (likely Granitic Pegmatite)

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

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Greisen

Greisen

Hypersthene

(Mg,Fe)SiO3 - Enstatite-Ferrosilite series

Chert (specifically Silex or Flint)

Microcrystalline Quartz (SiO2)

Likely polished leopard-skin jasper or brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the image alone

Onyx (Calcite Onyx / Mexican Onyx)

Calcium Carbonate (CaCO3)

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

Ferrous Slag

Iron/Steel Slag (Complex Calcium-Alumino-Silicates)

Blue Slag Glass

Amorphous Silica (Byproduct of smelting)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Ocean Jasper (Orbicular Jasper)

Silica (SiO2) with varied mineral inclusions

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Banded Gneiss

Gneiss (pronounced 'nice')

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Slag (Industrial Glass/Metal)

Ferrous slag or Glassy silicate byproduct

Pearl (likely Freshwater or Akoya Cultured)

Aragonite / Conchiolin composite (CaCO3)

Red Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Cubic Zirconia

Zirconium dioxide (ZrO2)

Ferrochrome Slag

Industrial Glassy Slag (Fe-Cr alloy byproduct)