Igneous And Metamorphic Derivative (Weathered)

Banded gneiss pebble

Gneiss, composed chiefly of quartz, feldspar, and mica/amphibole

Polished chrysoprase (likely)

Chrysoprase, nickel-bearing chalcedony (microcrystalline SiO₂)

Quartz-rich metamorphic rock (likely mica schist or gneiss)

Quartz–feldspar–mica assemblage; probable biotite schist/gneiss

Tumbled quartz pebble (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Rounded quartz-rich river pebble

Likely granitic or quartzitic clast; predominantly quartz (SiO₂) with feldspar and minor mica/iron oxides

Banded Agate (Yellow Agate)

Silicon Dioxide (SiO2)

Weathered granitic rock (likely granite or granodiorite)

Granite–granodiorite; mainly quartz, feldspar, and mica/hornblende

Iron-stained Quartz Pebble

Crystalline Silicon Dioxide (SiO2) with Hematite/Limonite staining

Quartz pebble with iron staining

Silicon dioxide (SiO2) with iron oxide impurities

Quartz (Gravel Pebble)

Silicon Dioxide (SiO2)

Quartz Pebble (with Feldspar/Mica)

Granitic Quartz / SiO2 with KAlSi3O8

Pebble Gravel Mix (Quartzite, Basalt, Chert)

Alluvial River Gravel / Aggregate Clasts

Kaolinite (Kaolin)

Kaolinite (Al2Si2O5(OH)4)

Weathered quartz-rich pebble

Milky quartz, chiefly silicon dioxide (SiO₂), possibly with iron-oxide staining and minor feldspar

Quartz with Actinolite or Tourmaline inclusions

Silicon Dioxide (SiO2) with Ca2(Mg,Fe)5Si8O22(OH)2 or Tourmaline group inclusions

Likely mica-rich schist

Mica schist, probably muscovite–biotite schist with quartz and feldspar

Pyrite Cube in Matrix

Iron Sulfide (FeS2)

Dark weathered metamorphic rock, likely schist or phyllite

Undetermined; probably mica-rich quartz–feldspar schist/phyllite

Weathered quartz-rich rock, possibly quartzite

Quartzite (mostly SiO₂), though a feldspathic sandstone or weathered granite fragment is also possible

Milky quartz

Quartz, silicon dioxide (SiO₂)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartzite with Feldspar and Mica (Granitic Gneiss Pebble)

Metamorphic Rock / Quartzite / Granitic Gneiss

Rounded quartz-rich pebble

Massive quartz (silicon dioxide, SiO₂), possibly milky quartz or quartzite

Milky quartz fragment

Quartz, silicon dioxide (SiO₂)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Rough Corundum (likely Sapphire/Zircon-bearing)

Aluminium Oxide (Al2O3)

Ruby

Corundum (Al2O3) with Chromium traces

Weathered granite (likely with accessory quartz)

Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende

Likely weathered granite or granitic pegmatite fragment

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

Dark fine-grained igneous rock, likely basalt

Basalt; commonly composed of plagioclase feldspar, pyroxene, and minor olivine or magnetite

Granite

Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

Magnetite-rich ironstone

Magnetite, Fe₃O₄, likely in a dense ironstone matrix

Weathered metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica schist/gneiss; exact identification is uncertain from the photograph

Uncertain pale granitoid or weathered feldspathic rock

Likely granite or granodiorite; chiefly quartz, feldspar, and minor mica, but the photograph is insufficient for precise identification.

Quartz-bearing metamorphic rock, likely schist or quartzite

Quartz (SiO₂) in a mica-rich metamorphic matrix

Rounded granite or granitic pebble

Granite; mainly quartz, feldspar, and mica (exact identification is uncertain from the photograph)

Coarse-grained granite or granitic gneiss

Granite; chiefly quartz (SiO₂), feldspar, and dark mica/amphibole. Strong foliation could indicate granitic gneiss.

Weathered granite or granitic gneiss

Granite, chiefly quartz, feldspar, and mica; exact identification is uncertain from the photograph

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Weathered quartz-rich metamorphic rock (likely gneiss or quartzite)

Quartz (SiO₂) with probable feldspar, mica, and iron-oxide alteration

Quartz (Milky/Crystalline fragment)

Silicon Dioxide (SiO2)