Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Quartz Pebble

Silicon Dioxide (SiO2)

Green Onyx (Banded Calcite)

Travertine (CaCO3 - Calcium Carbonate)

Limonite (vibrant yellowish-brown iron oxide)

Limonite (FeO(OH)·nH2O)

Weathered vesicular volcanic rock, likely basaltic scoria

Vesicular basalt/scoria; mainly plagioclase, pyroxene, and iron-rich glass or oxides

Red Jasper with Quartz Veins

Microcrystalline Quartz (SiO2) with Hematite impurities

Likely iron meteorite (stony-iron or weathered iron-rich meteorite)

Provisional identification: meteoritic Fe–Ni alloy, mainly kamacite/taenite; exact classification requires chemical and petrographic testing

Iron meteorite candidate

Fe–Ni metallic meteorite, possibly an iron meteorite fragment

Quartz Druzy in Chert Pebble

Silicon Dioxide (SiO2) - Microcrystalline & Crystalline Quartz

Sandstone

Arenite (Silicon Dioxide, SiO2 based)

Quartz River Pebble (Iron-Stained)

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Pitted Limestone

Calcium Carbonate (CaCO3)

Rounded river pebble, likely basaltic or andesitic volcanic rock

Fine-grained mafic to intermediate volcanic rock; likely basalt/andesite, but exact identification requires testing

Hematite

Iron(III) oxide (Fe2O3)

Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

Quartz fragment

Quartz (silicon dioxide, SiO₂)

Vuggy Chert / Silicified Limestone

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Dalmatian jasper (likely orbicular microgranite)

Quartz–feldspar–biotite/pyroxene microgranite; commonly marketed as Dalmatian jasper

Sandstone

Arenite (SiO2 based)

Hematite

Iron(III) oxide (Fe2O3)

Rhodochrosite

Manganese Carbonate (MnCO3)

Porphyritic volcanic rock, likely andesite or basaltic andesite

Fine-grained plagioclase–pyroxene volcanic rock; exact identification requires microscopy or chemical testing

Red Jasper

Silicon Dioxide with Hematite (SiO2 + Fe2O3)

Small rounded pebble, likely quartz-rich sandstone or granitoid fragment

Uncertain; probable quartz/feldspar-bearing lithic pebble

Agate (Carnelian type)

Silicon Dioxide (SiO2)

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Agate

Chalcedony (SiO2) with impurities

River Pebble (Siltstone / Sandstone Pebble)

Sedimentary Rock (Quartz, Feldspar, Clay Minerals)

Agate / Chalcedony Pebble

Silicon Dioxide (SiO2)

Porphyritic basalt (likely amygdaloidal basalt)

Basalt, a mafic volcanic rock; composition typically plagioclase + pyroxene, with possible olivine and vesicle-filling minerals

Banded River Rock / Gneiss (highly weathered)

Gneiss

Chalcedony/Agate

Cryptocrystalline Silica (SiO2)

Banded Chert

Silicon Dioxide (SiO2) with impurities

Goethite / Limonite Gossan

Hydrated Iron Oxide (FeO(OH))

Porphyritic basalt (likely amygdaloidal basalt)

Basalt containing larger plagioclase crystals and pale vesicle-fill minerals, commonly calcite, zeolite, or quartz

Gossan (Iron Hat)

Limonitic Gossan (Fe2O3·nH2O)

Honey Calcite

Calcium Carbonate (CaCO3)

Fossil ammonite

Ammonite (subclass Ammonoidea; exact species not identifiable from the image)

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

Fossilized marine shell fragment

Likely a bivalve or gastropod shell preserved as calcite (CaCO₃)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Native Silver Nugget

Silver (Ag)

Weathered Sedimentary Rock

Sedimentary Rock