Mineraloid (Synthetic)

Chert or flint nodule

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

Porphyritic Rhyolite or Andesite (Porphyry)

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

Brick

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

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)

Charoite

Charoite (K(Ca,Na)2Si4O10(OH,F)·nH2O)

Hypersthene

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

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)

Rose Quartz

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

Ocean Jasper (Orbicular Jasper)

Silica (SiO2) with varied mineral inclusions

Banded Gneiss

Gneiss (pronounced 'nice')

Sugilite

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

Pearl (likely Freshwater or Akoya Cultured)

Aragonite / Conchiolin composite (CaCO3)

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)

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.

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Tektite (Indochinite)

Tektite (High-silica natural glass)