Mineral (Native Element Alloy)

Petrified Wood

Silicified Wood (primarily SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Clear Quartz

Silicon Dioxide (SiO2)

Malachite Coating on Host Rock

Malachite [Cu2CO3(OH)2]

Aventurine (likely Green Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Biotite Schist with Garnet

Garnet-Biotite Schist

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Cloudy Quartz

Silicon Dioxide (SiO2)

Granite (Orthoclase rich)

Granite (composed primarily of Quartz and Potassium Feldspar KAlSi3O8)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Sandstone (River Rock)

Arenite (composed primarily of SiO2)

Chrysocolla in Matrix

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Note: Item is not a geological specimen

n/a

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.

Pearl

Calcium Carbonate (CaCO3) - mainly Aragonite and Calcite

Biotite (Mica)

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

Sandstone (with potential mineral inclusions)

Clastic sedimentary rock (primarily Quartz, SiO2)

Eudialyte

Eudialyte (Na4(Ca,Ce)2(Fe2+,Mn,Y)ZrSi8O22(OH,Cl)2)

Pegmatite

Coarse-grained Igneous Rock (Granitic Pegmatite)

Gneiss

Gneiss

Gneiss (specifically Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)

Coarse-grained Granite

Granitoid (KAlSi3O8 + SiO2 + NaAlSi3O8)

Granite

Granite (Felsic Plutonic Rock)

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

Aquamarine

Beryl (Be3Al2Si6O18 with trace Fe2+)

Epidote

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

Limonite (Iron Ore)

Limonite; FeO(OH)·nH2O

Eclogite

Eclogite (Omphacite + Pyrope)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Bornite

Bornite (Cu5FeS4)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Yellow Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Shale

Laminated Mudstone

Granitic Pegmatite

Granite Pegmatite (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Muscovite)