Minerals

Weathered schist

Mica schist, typically quartz–mica schist

Quartz with Associated Minerals

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)

Gneiss (complex silicate composition)

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered iron-stained granite or granitic gneiss

Quartz–feldspar–mica granitoid, likely altered and weathered

Weathered foliated metamorphic rock, likely schist or phyllite

Micaceous quartz–feldspar schist/phyllite; exact identification requires microscopy or testing

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered granitic rock

Granite or granodiorite, likely quartz–feldspar–mica aggregate

Dinosaur Bone

Agatized Dinosaur Bone

Epidote-bearing basalt

Basalt with epidote-group mineral inclusions, likely epidote or pistachite (Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH))

Weathered quartz-bearing rock, possibly granite or gneiss

Indeterminate; likely quartz–feldspar–mica aggregate, possibly granitic gneiss

Copper-bearing metamorphic rock, likely bornite- or chalcopyrite-rich schist

Quartz–mica schist with disseminated copper sulfides; possible bornite (Cu₅FeS₄) and chalcopyrite (CuFeS₂)

Pegmatite

Igneous Pegmatite

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Tumbled basalt

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

Schist with Biotite and Quartz

Biotite-Quartz Schist (Fe,Mg,Al silicate mix)

Given the appearance, it's likely a fragment of an igneous or metamorphic rock composed of multiple minerals. Without specific diagnostic features, it's difficult to give a common name other than 'crystalline rock fragment'. If pressed to guess based on the granular, somewhat light and dark speckled appearance, it could be a fragment of granite or a related intrusive igneous rock.

As a rock fragment, it does not have a single scientific mineral name; rather, it's a piece of a rock which is a combination of minerals. If it were granite, its main mineral composition would be quartz (SiO2), feldspar (e.g., KAlSi3O8 - orthoclase, (Na,Ca)(Al,Si)4O8 - plagioclase), and mica (e.g., KAl2(AlSi3O10)(OH)2 - muscovite or K(Mg,Fe)3AlSi3O10(OH)2 - biotite), among others.

Likely quartz-rich mineral specimen

Quartz (SiO₂), possibly milky quartz or quartz-bearing rock

Quartz-rich pegmatite fragment

Granite/pegmatite; chiefly quartz (SiO₂) and feldspar, with possible biotite or tourmaline

Azurite and Malachite on Matrix

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2CO3(OH)2

Greenstone

Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote

Diorite

Diorite (intermediate intrusive igneous rock)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Polished granite

Granite; chiefly quartz, feldspar, and mica/amphibole

Red Sandstone

Arenite (Ferruginous Sandstone)

Vanadinite

Lead Chlorovanadate, Pb5(VO4)3Cl

Granitic Gneiss

Gneiss (Metamorphic Rock)

Serpentine-bearing metamorphic rock (likely chromite/vesuvianite-bearing serpentinite)

Serpentinite, chiefly serpentine-group minerals [(Mg,Fe)₃Si₂O₅(OH)₄], with dark accessory minerals

Polished copper-bearing mineral specimen, likely malachite-rich copper ore

Malachite, Cu₂CO₃(OH)₂, possibly mixed with chrysocolla or limonite

Weathered vesicular basalt (likely amygdaloidal basalt)

Basalt, chiefly plagioclase + pyroxene ± olivine; cavities may contain secondary zeolites, calcite, or chlorite

Dark gray fine-grained rock, possibly basalt

Basalt; primarily plagioclase feldspar and pyroxene, with possible olivine or magnetite

Milky quartz (rough quartz specimen)

Quartz, silicon dioxide (SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble

Silicon Dioxide (SiO2)

Greenstone

Metabasalt / Chlorite-actinolite-epidote schist