Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Brecciated Jasper

Microcrystalline Quartz (SiO2)

Rounded sandstone or quartz-rich sedimentary pebble

Likely quartz arenite/subarkose; exact identification requires testing

Pyrite (Iron Pyrite) with Goethite Oxidation

Iron Sulfide (FeS2)

Weathered vesicular volcanic rock (likely pumice/tuff)

Porous volcanic pyroclastic rock, probably pumiceous tuff; exact identification requires testing

Chert with Quartz/Calcite Vein

Microcrystalline Silica (SiO2)

Iron-stained quartz fragment (probable quartzite or chert)

Quartz, SiO₂; possibly iron-oxide-stained microcrystalline silica

Iron-rich sandstone or lateritic ironstone pebble

Ferruginous sandstone/ironstone, composed mainly of quartz (SiO₂) and iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Turquoise

CuAl6(PO4)4(OH)8"""""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" """""""""" • 4H2O (Hydrated copper and aluminum phosphate)

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper aluminum phosphate)

Quartz Geode

Silicon Dioxide (SiO2) in Geode form

Polished black stone, likely hematite or black jasper

Hematite (Fe₂O₃) or opaque chalcedony/jasper (SiO₂); image-only identification is uncertain

Likely weathered iron-rich breccia or jasper

Silicified iron-oxide breccia; exact identification requires testing

Polished fossiliferous chert or silicified limestone pebble

Microcrystalline quartz (SiO₂), possibly with calcite and iron-oxide inclusions

Iron-stained quartz vein rock

Quartz-rich vein material, predominantly SiO₂, with iron oxyhydroxides (goethite/limonite) and likely sulfide alteration

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Fossiliferous Limestone

Biomicrite / Fossiliferous Limestone (CaCO3)

Vesicular volcanic rock, likely scoria

Scoria (vesicular basaltic-andesitic rock), composed mainly of plagioclase, pyroxene, and volcanic glass

Limonite Geode (Ironstone Concretion)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Quartz Pebble

Silicon Dioxide (SiO2)

Weathered quartz-rich pebble

Likely quartz aggregate, SiO₂, possibly quartzite or silicified rock

Scoriaceous basalt (volcanic scoria)

Vesicular basalt; commonly pyroxene–plagioclase basalt with iron-rich glass

Sandstone with Liesegang Rings

Arenite with Iron Oxide Concretions

Quartz (Citrine or Smoky variety)

Silicon Dioxide (SiO2)

Metallic sulfide mineral specimen, likely pyrite

Pyrite (FeS₂), possibly mixed with marcasite or another iron sulfide

Tumbled brown mineral/rock specimen

Indeterminate from image; likely brown jasper, chert, or iron-stained quartzite

Jasper with Quartz Vein

Silicon Dioxide (SiO2)

Sandstone (Weathered)

Arenite (primarily SiO2)

Carnelian

Carnelian (Cryptocrystalline Quartz, SiO2)

Tumbled white mineral fragment

Indeterminate; possibly milky quartz or calcite

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Mixed rock and mineral specimen collection

Varied silicate, carbonate, and oxide minerals; individual identification is not possible from this group photograph

Tumbled brown jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide impurities

Hematite

Iron(III) oxide (Fe2O3)

Sulfur on Quartz

Native Sulfur (S8) with Quartz (SiO2)

Weathered conglomeratic rock, likely iron-stained sandstone

Probable ferruginous, clast-bearing sandstone; exact identification requires examination of a fresh surface

Turquoise

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

Quartz Geode

Silicon Dioxide (SiO2)

Likely calcite-rich limestone

Calcite (CaCO₃), probably micritic or fossiliferous limestone

Limonite (Yellow Ochre)

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

Agate

Silicon Dioxide / Cryptocrystalline Quartz (SiO2)

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)

Limonite (Iron Ore/Bog Iron)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)