Mineralological Specimen

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Pumice

Pumice (Volcanic glass / Felsic extrusive rock)

Unknown Dark Stone

Unknown

Granite

Intrusive Igneous Rock

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially altered granite

Sandstone

Arenite (SiO2 based)

Botryoidal Agate / Chalcedony Geode

Silicon Dioxide (SiO2)

Chalcedony (Agate/Carnelian variant)

Silicon Dioxide (SiO2)

Rough Quartz (or Quartzite pebble)

Silicon Dioxide (SiO2)

Tumbled basalt

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase, pyroxene, and commonly olivine

Tumbled yellow calcite (probable)

Calcite — calcium carbonate, CaCO₃

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (Jasper)

Silicon Dioxide (SiO2)

Brown Quartz (Jasper or Chert)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2) with iron impurities

Vesicular volcanic rock (likely pumice or scoria)

Vesicular volcanic rock; exact composition cannot be determined from the photo

Unidentified small mineral specimen

Indeterminate from the photograph; it may be a light-colored quartz- or feldspar-rich rock with a dark mineral inclusion.

Quartz Geode

Silicon Dioxide (SiO₂)

Emerald with Matrix (Emerald in Mica Schist)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Yellow Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Quartz Geode with Calcite/Siderite

Crystalline Silicon Dioxide (SiO2) with Carbonate inclusions

Small polished pebble, likely quartz or quartzite

Undetermined; possibly quartzite (quartz, SiO₂)

Likely banded ironstone (possibly a polished or naturally smoothed piece)

Iron-rich chert/jasper with iron oxides; exact identification is uncertain from the small, indirect image

Faceted colorless gemstone, likely quartz (rock crystal)

Quartz, SiO₂

White tumbled stone, possibly quartz or marble

Unidentified; appearance alone cannot distinguish quartz (SiO₂) from calcite-rich marble (CaCO₃).

Polished plume agate

Microcrystalline quartz (SiO₂), variety of chalcedony

Blue-gray stone fragment, possibly slate or fine-grained basalt

Undetermined; appearance is consistent with slate (fine-grained metamorphosed mudstone), but the image is insufficient for reliable identification.

Tumbled jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and other mineral inclusions

Fossiliferous Limestone or Shale

Biomicrite (if limestone) or Fossiliferous Shale

Tumbled orange feldspar (likely sunstone or orange aventurine)

Alkali feldspar, commonly orthoclase or microcline; approximate composition KAlSi₃O₈

Polished dendritic agate cabochon

Microcrystalline quartz (chalcedony), SiO₂, with iron/manganese dendrites and possible plume inclusions

Likely rough pink feldspar or rose quartz

Most likely microcline feldspar (KAlSi₃O₈) or rose quartz (SiO₂)

Granite

Granite (Phaneritic Quartz-Feldspar rock)

Quartz Geode in Sedimentary Host Rock

Silicon Dioxide (SiO2) in Carbonate Matrix

Brecciated Jasper

SiO2 (Silicon Dioxide)

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2) with Hematite/Limonite

Chert (Common Opal/Agatized Rock)

Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica

Clear Quartz with Limonite

Silicon Dioxide (SiO2) with Hydrated Iron Oxides

Petrified Wood

Silicified Wood (SiO2)

Unidentified gray rock/mineral specimen

Indeterminate; possibly quartz-rich rock or a metallic sulfide-bearing specimen