Sedimentary Or Metamorphic (Base Substrate)

Muscovite Mica

Muscovite / KAl2(AlSi3O10)(OH)2

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

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.

Citrine

Crystalline Quartz (SiO2) with iron impurities

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Blue Quartzite

Quartzite (silicon dioxide, SiO2)

Epidote

Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Epidote

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Rhodonite

Rhodonite (Manganese silicate), (Mn,Fe,Mg,Ca)SiO3

Marble

Metamorphosed Limestone (principally CaCO3)

Sunstone

Oligoclase (Plagioclase Feldspar subclass), (Ca,Na)(Al,Si)4O8

Red Garnet

Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)

Citrine Quartz

SiO2 (Silicon Dioxide with Iron impurities)

Biotite or Phlogopite Mica

K(Mg,Fe)3(AlSi3O10)(F,OH)2

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Quartzite with Iron Inclusions

Metamorphosed Quartz Sandstone (SiO2 with Fe2O3)

Citrine (Heat-treated Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Milky Quartz

Silicon Dioxide (SiO2)

Epidote

Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Blue Apatite

Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock)

Quartzite

Quartzite (SiO2)

Quartzite Pebble

Quartzite (SiO2)

Basalt with Epidote (Greenstone)

Epidote-bearing Metabasalt

Engineer Quartz/Quartzite

SiO2 (Silicon Dioxide with binders)

Painted River Rock

Anthropogenic-modified Siliciclastic Sedimentary Rock

Fuchsite

Chrome-bearing Muscovite [K(Al,Cr)2(AlSi3O10)(OH)2]

Rainbow Moonstone with Black Tourmaline

White Labradorite with Schorl (Na,Ca)(Al,Si)4O8

Chert (Common Chert)

Cryptocrystalline Quartz (SiO2)

Corundum (Sapphire/Ruby in Matrix)

Aluminium oxide (Al2O3)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Slate

Phyllo-silicate based metamorphic rock

Anthracite Coal

Anthracite (Carbon-based metamorphic rock)

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

Biotite (Mica)

K(Mg,Fe)3AlSi3O10(OH,F)2

Graphite

Graphite (C)

Beryl (Aquamarine) in Matrix with Schorl

Be3Al2Si6O18 (Beryl) with NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

River Rock (Quartzite)

Quartzite (SiO2)

Jasper in Quartzite (likely Cinnabar or Iron inclusions)

Silicon dioxide (SiO2) with impurities

Blue Sapphire (in a faceted jewelry setting)

Corundum (Al2O3) with trace Iron and Titanium

Muscovite Mica

KAl2(AlSi3O10)(F,OH)2