Mineral With Metamorphic Or Igneous Host

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Quartz (Raw Chunk)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Ruby (Corundum)

Aluminum Oxide (Al2O3) with Chromium traces

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.

Quartz (Milky or Citrine-tinted)

Silicon Dioxide (SiO2)

Quartz / Quartz Cluster

Silicon Dioxide (SiO2)

Rose Quartz

Rose Quartz (SiO2)

Gneiss with Quartz/Feldspar Vein

Quartz-Feldspathic Gneiss

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Pyrite

Iron Disulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Chlorite Included Quartz

Silicon Dioxide (SiO2) with Chlorite (Mg,Fe,Li)6AlSi3O10(OH)8

Smoky Quartz

Silicon Dioxide (SiO2)

Rainbow Moonstone with Black Tourmaline

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

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz (Grain/Fragment)

Silicon Dioxide (SiO2)

Quartz (specifically Milky or Clear Quartz)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Feldspar (specifically Orthoclase)

Potassium aluminum silicate (KAlSi3O8)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Copper-bearing Quartz (with Malachite and Iron Oxides)

Quartz (SiO2) with Malachite (Cu2CO3(OH)2) and Hematite/Limonite (Fe2O3)

Garnet (Almandine)

Almandine Fe3Al2(SiO4)3

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Blue Apatite

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

Chalcopyrite (Peacock Ore)

Copper Iron Sulfide (CuFeS2)

Citrine Quartz

Silicon Dioxide (SiO2)

Rainbow Hematite Ring

Iron(III) oxide (Fe2O3) with thin-film coating

Milky Quartz

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO₂)

Pyrite

Iron Sulfide (FeS2)

Quartz Pebble

Silicon Dioxide (SiO2)

Biotite on Quartz

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