Unknown (Likely Sedimentary Or Metamorphic)

Quartz Vein in Hematitic Siltstone

Hydrothermal Quartz (SiO2) in Ferriferous Matrix

Quartz Vein in Host Rock (Likely Slate or Shale)

Hydrothermal Quartz (SiO2) in Pelitic host rock

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Small metallic mineral fragment, possibly galena or slag-like sulfide

Tentatively galena (PbS), but identification is uncertain from the image

Slate

Slate; fine-grained metamorphosed shale, commonly quartz–muscovite/chlorite rich

Coarse-grained granite

Granite; predominantly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Porphyritic volcanic rock (likely andesite or basaltic andesite)

Porphyritic andesite/basaltic andesite; mainly plagioclase, pyroxene, and possibly olivine in a fine volcanic groundmass

Likely quartz-rich stone (possibly milky quartz or quartzite)

Quartz, silicon dioxide (SiO₂), or quartzite if interlocking grains are present

Quartz-veined metamorphic rock, likely mica schist

Mica schist with a milky-quartz vein; predominantly quartz, feldspar, and biotite/muscovite mica

Gneiss (specifically Granitic Gneiss)

Gneissic Metamorphic Rock

Weathered brown rock, likely sandstone or iron-rich quartzite

Indeterminate; probable quartz-rich sandstone (quartz, feldspar, iron oxides)

Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

Unknown dark mineral/rock fragment

Indeterminate; possibly a dark sulfide mineral or slag-like geological fragment

Likely slate fragment

Slate; predominantly fine-grained mica/clay minerals and quartz

Garnet-bearing metamorphic rock, likely garnet schist or amphibolite

Almandine garnet (Fe₃Al₂Si₃O₁₂) in mica- or amphibole-rich matrix

Quartz pebble with iron staining

SiO2

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Polished banded gneiss pebble

Gneiss, chiefly quartz–feldspar–mica; exact mineralogy uncertain from image

Weathered jasper or iron-stained quartzite

Silicified quartz-rich rock, primarily microcrystalline quartz (SiO₂) with iron-oxide/hydroxide staining

Yellow Agate

Agate (Varietal form of Chalcedony/Quartz, SiO2)

Weathered brown river pebble, likely sandstone or iron-rich quartzite

Indeterminate; probable quartz-rich sandstone (quartz and iron-oxide cement)

Weathered fine-grained stone, likely sandstone or quartzite

Quartz-rich sandstone (possibly weakly metamorphosed quartzite); predominantly SiO₂

Jasper with Hematite Inclusions

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)

Quartz

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Malaysian 50 Sen Coin

Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)

Probable mica schist

Schist, likely muscovite–biotite schist

Beach Pebbles and Quartz Aggregates

Quartz pebbles and biogenic fragments (SiO2, CaCO3)

Green Calcite

Calcium Carbonate (CaCO3)

Foliated metamorphic rock, likely gneiss or mica schist

Quartz–feldspar–mica metamorphic rock; exact identification is uncertain from the photograph

Banded gneiss fragment

Gneiss, likely quartz–feldspar–mica gneiss

Painted River Rock

Artificially Coated Sedimentary Rock

Banded gneiss pebble

Gneiss, commonly quartz–feldspar–mica gneiss

Specular Hematite with Quartz and Limonite

Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)

Red Jasper (Quartzite)

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled banded quartzite or jasper

Silica-rich quartzite; likely iron-oxide-stained quartz (SiO₂)

Likely weathered metamorphic rock (quartzite or schist)

Quartz-rich foliated metamorphic rock; exact identification requires testing

Quartz pebble

Silicon dioxide (SiO2)

Biotite-rich gneiss

Gneiss, likely quartz–feldspar–biotite gneiss

Tumbled quartz-rich carbonate rock

Likely massive quartz (SiO₂), possibly calcite-bearing marble or limestone

Pyrite-bearing rock, possibly pyrite-rich schist or quartzite

Pyrite (iron disulfide, FeS₂) in a fine-grained metamorphic or quartz-rich matrix

Gneiss

Gneiss