Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Quartz (with iron oxide staining)

Silicon Dioxide (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) on Sedimentary Host Rock

Sandstone

Arenite (primarily SiO2)

Likely quartz-rich pebble or weathered limestone fragment

Indeterminate; possibly microcrystalline quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Limonite (Ironstone Concretion)

Limonite (FeO(OH)·nH2O)

Limonite/Goethite Nodule

Iron Oxyhydroxide (primarily FeO(OH)·nH2O)

Siltstone with Weathering Crust

Siltstone (primarily SiO2 with Al2O3)

Vesicular basalt (likely weathered basalt scoria)

Basalt; predominantly plagioclase, clinopyroxene, and iron-rich minerals, with possible secondary zeolite/calcite coatings

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O

Vesicular basalt (possibly scoriaceous basalt)

Basalt; predominantly plagioclase feldspar, clinopyroxene, and Fe-Ti oxides, with possible olivine

Turquoise

Hydrate phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

Weathered sandstone

Quartz-rich clastic sandstone, likely ferruginous arkose or litharenite

Sandstone with Quartz Veining

Clastic sedimentary rock (SiO2 dominated)

Vesicular basalt with zeolite or calcite amygdules

Basalt; commonly plagioclase–clinopyroxene–olivine, with secondary zeolite/calcite fillings

Weathered copper-bearing volcanic rock (likely altered basalt/andesite)

Hydrothermally altered basalt or andesite; green coloration may reflect chlorite, epidote, or copper minerals such as chrysocolla

Green Calcite

Calcium Carbonate (CaCO3)

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

Quartz Geode with Agate

Silicon Dioxide (SiO2)

Copper Ore (Chrysocolla/Malachite in host rock)

Hydrated copper phyllosilicate and copper carbonate hydroxide

Limonite (Iron Ore/Hydrated Iron Oxide)

Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))

Vesicular basalt (possibly scoriaceous basalt)

Basalt, primarily plagioclase + pyroxene ± olivine; vesicles commonly lined or filled with secondary zeolites/calcite

Weathered chert or siliceous limestone

Microcrystalline quartz (SiO₂), possibly with carbonate matrix

Limonite Nugget

Limonite (Hydrated iron oxide-hydroxide, FeO(OH)·nH2O)

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Limonite (Iron Ore / Ochre)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Weathered basaltic rock

Basalt, likely amygdaloidal or altered basalt (plagioclase–pyroxene ± olivine)

Blue Calcite

Calcium Carbonate (CaCO3)

Weathered Sandstone / Quartzite

Quartz Arenite

Limonite and Goethite on Gossan

FeO(OH)·nH2O

Turquoise

Turquoise, CuAl6(PO4)4(OH)8·4H2O

Native Copper with Malachite and Chrysocolla

Native Copper (Cu) with Malachite [Cu2CO3(OH)2] and Chrysocolla [(Cu,Al)2H2Si2O5(OH)4·nH2O]

Agate (or Chalcedony)

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Agate

Silicon dioxide (SiO2) - variety of chalcedony

Polished leopard jasper (orbicular or brecciated jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions

Iron-stained weathered volcanic rock (probable basalt/andesite)

Altered basaltic–andesitic rock, chiefly plagioclase and pyroxene with iron oxides/hydroxides

Green Calcite

Calcium Carbonate (CaCO3)