Igneous And Metamorphic Derivative (Weathered)

Weathered Pyrite Nodule

Iron Sulfide (FeS2) undergoing oxidation to limonite/goethite

Quartz Pebble

Silicon Dioxide (SiO2)

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Weathered granite or granitic gneiss

Granite; primarily quartz, feldspar, and mica

Likely weathered granite or granitic pegmatite

Granite; chiefly quartz (SiO₂), feldspar, and mica

Basalt (Weathered River Pebble)

Extrusive Igneous Rock

Quartz vein fragment

Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions

Yellow Sapphire (Pukhraj)

Corundum (Al2O3)

Quartz pebble

Silicon dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Schist or Gneiss pebble

Metamorphic rock (Schist/Gneiss)

Pyrite Nodules / Weathered Pyrite

Iron Sulfide (FeS2)

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly milky quartz or chalcedony

Milky quartz (iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

Unidentified small mineral fragments

Likely quartz- or feldspar-rich material; species cannot be determined reliably from the image

Small reddish-brown mineral fragment

Uncertain; possibly iron-stained quartz, feldspar, or garnet

Quartz-rich metamorphic rock (probable quartzite)

Quartzite; predominantly crystalline SiO₂, with possible mica and iron-oxide impurities

Tumbled quartz pebble (probable milky quartz)

Quartz, silicon dioxide (SiO₂)

Painted River Rock (likely Quartzite or Granite)

Quartzite or Granitic Gneiss (painted)

Quartz Fragment

Silicon Dioxide (SiO2)

Fossilized bivalve shell or shell-rich limestone

Likely an indeterminate fossil mollusk; calcite/aragonite (CaCO₃), possibly preserved in limestone

Tiny rounded brown mineral grain

Indeterminate; possibly iron oxide, garnet, or a weathered sulfide grain

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially altered granite

Unidentified small rock fragment

Likely quartz-rich material; exact identification is indeterminate from the image

Quartz Pebble

Silicon Dioxide (SiO2)

Unidentified gray-brown stone

Likely fine-grained quartz–feldspar rock; exact identification is not possible from this close, blurred image

Polished gray pebble, likely quartzite or fine-grained granite

Probable quartzite (mostly microcrystalline SiO₂); identification is uncertain from the photograph

Small pale mineral fragment

Unidentified; possibly quartz, calcite, or feldspar

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz-rich pebble

Mostly quartz (SiO₂), possibly a quartzite or vein-quartz fragment

Likely quartz-rich pebble

Quartz-bearing granite, granitic gneiss, or quartzite (indeterminate from photo)

Mixed polished rock/mineral specimens

Indeterminate from image; likely quartz-bearing material with iron-oxide staining and possibly mica-rich schist

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂), with hematite/goethite inclusions

Quartz Pebble

Silicon Dioxide (SiO2)

Rounded quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly chalcedony or milky quartz

Small rounded pebble (likely quartz or quartz-rich stone)

Uncertain; possibly microcrystalline quartz (SiO₂)

Quartz River Stone

Silicon Dioxide (SiO2)

Quartz Pebble (River Agate / Chalcedony)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)