Mineral (Extraterrestrial)

Pink Granite

Granite (Phaneritic Quartz-Feldspar Rock)

Gneiss

Gneiss

Malachite

Copper carbonate hydroxide, Cu2CO3(OH)2

Fluorite

Calcium Fluoride (CaF2)

Limonite Concretion (Goonie or Rattlestone)

Limonite (FeO(OH)·nH2O)

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Desert Rose

Gypsum (variety Selenite) or Barite: CaSO4 · 2H2O

Sandstone Concretion with Quartz Center

Sedimentary Clastic Rock (SiO2 matrix with Quartz core)

Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidote and Quartz)

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right)

Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)

Quartz Geode

Silicon dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Green Fluorite

Calcium Fluoride (CaF2)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Quartz (Milky/Rose variety)

Silicon Dioxide (SiO2)

Granite

Granite

Jadeite and Mixed Gemstones (Ruby, Sapphire, Emerald)

Jadeite (NaAlSi2O6), Corundum (Al2O3), Beryl (Be3Al2(Si6O18))

Granodiorite (or Granite) Pebble

Phaneritic Felsic Igneous Pebble

Note: Item is not a geological specimen

Homo sapiens (Dermal Appendage: Pilus)

Greenstone (Amygdaloidal Basalt)

Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)

Flesh-colored Quartz Mineral

SiO2 (Silicon Dioxide) with Iron Impurities

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide - SiO2)

Citrine

SiO2 (Silicon Dioxide)

Granite with Hematite staining

Granitoid (Quartz, Feldspar, Mica) with Iron Oxide (Fe2O3)

Tree Agate

Silicon dioxide (SiO2)

Covellite

Covellite (CuS)

Red Sandstone

Arenite (primarily Quartz with Iron Oxide coating)

Schist (Micaceous)

Mica Schist

Sandstone (likely Quartzose Sandstone pebble)

Arenite (primarily SiO2)

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, chlorite, and micas)

Granite

Granite

Amygdaloidal Basalt

Vesicular-Amygdaloidal Basalt (Mafic Extrusive)

Educational Geologic Collection

Mixed Mineral and Rock Collection (Various compositions)

Turquoise in Matrix

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Fluorite (Rainbow or Multi-colored Fluorite)

Fluorite (Calcium Fluoride - CaF2)

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.

Schist with Biotite and Quartz

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

Limonite Geode (Ironstone Concretion)

Limonite [FeO(OH)·nH2O] with possible Quartz or Calcite interior

Malachite

Malachite (Copper Carbonate Hydroxide, Cu2CO3(OH)2)

Granite

Granite

Pebble

Clast (specifically a granule or small pebble)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)