Mineral, Specifically A Rock Fragment

African Turquoise

Jasper / Quartz matrix (Trade name: African Turquoise, chemically a form of microcrystalline quartz with various mineral inclusions)

Likely silver-gray metallic ore fragment

Unidentified metallic mineral; possibly galena (PbS), but the image is insufficient for a confident identification

Unidentified rough rock fragment

Undetermined; the image does not show enough diagnostic detail for a reliable rock identification

River Pebble

Quartzo-feldspathic rock fragment

Weathered pale-blue rock fragment

Unidentified; the image does not show enough detail for a reliable geological identification

Pink Granite

Phaneritic Felsic Igneous Rock

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)

Greenish-gray rock fragment, likely serpentine-rich stone

Possibly serpentinite (serpentine-group minerals; identification is uncertain from the image)

Conglomerate

Lithified, poorly sorted gravel; composition is uncertain from the image

Breccia

Clastic Breccia

Granite

Plutonic felsic igneous rock

Ironstone Concretion (Coprolite-like)

Goethite/Hematite Siderite Spheroid (FeCO3 or FeO(OH))

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Iron-stained quartz-rich rock (possibly ironstone)

Quartz (SiO₂) with iron-oxide/hydroxide staining, likely limonite/goethite

Sandstone (with garnet granules)

Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)

Granite Pebble

Phaneritic Felsic Igneous Rock (Granite)

Fire Opal (in Matrix)

Hydrated Silica (SiO2·nH2O)

Dendritic Agate (specifically Orange/Tumbled)

Silicon Dioxide (SiO2) with Oxide Inclusions

Pebble (likely Sandstone or Granitic Pebble)

Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)

Fossil Coral (Petoskey-style Rugose Coral)

Hexagonaria percarinata (Order: Rugosa)

Dark rock/mineral fragment

Undetermined; possibly magnetite-rich basalt or iron sulfide

Granite fragment

Granite; mainly quartz (SiO₂), feldspar, and mica

Milky Quartz

Silicon Dioxide (SiO2)

Small rounded stone or mineral fragment

Indeterminate; likely a common quartz- or feldspar-bearing silicate fragment

Quartz (Agate/Chalcedony variety)

Silicon Dioxide (SiO2)

Weathered quartz-rich rock fragment

Indeterminate; likely quartz-bearing silicate rock

Milky Quartz

Silicon Dioxide (SiO2)

Ocean Jasper

Spherulitic Chalcedony (SiO2)

Likely banded gneiss fragment

Gneiss, a foliated metamorphic rock (exact mineral identification is uncertain from the image)

Unknown small pale rock fragment

Unidentified light-colored granular mineral aggregate; likely quartz-rich material or limestone

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Veined Rock (Likely Graywacke or Quartzite)

Silicon Dioxide (SiO2) veins in Metasedimentary matrix

Quartz (Druzy or Crystalline)

Silicon Dioxide (SiO2)

Pebble

Lithic fragment / Rounded rock fragment

Likely weathered iron-rich breccia or jasper

Silicified iron-oxide breccia; exact identification requires testing

Ruby zoisite (anyolite)

Zoisite with corundum (ruby) and commonly amphibole; Ca₂Al₃(SiO₄)₃(OH)

Granite

Granite (Felsic Plutonic Rock)

Dark, coarse-grained rock fragment (possibly amphibolite or gabbro)

Uncertain from the photo; likely amphibolite (hornblende-rich metamorphic rock) or a mafic igneous rock such as gabbro

Quartz Geode

Crystalline Silicon Dioxide (SiO2) within a geode structure

Serpentine

Serpentine Group (Mg3Si2O5(OH)4)

Flower Agate (Plume Agate)

Chalcedony (Silicon Dioxide) with Spherulitic Inclusions - SiO2

Small dark rock fragment (unidentified)

Undetermined; the image does not show enough detail for reliable identification.