Mineral Variant

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Red Sandstone

Arenite (Ferruginous Sandstone)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Silver (Native Silver Mineral)

Ag (Native Silver), Alloyed 90% Ag / 10% Cu

General Rock and Mineral Collection (Center: Angelite / Blue Anhydrite)

Anhydrite (Calcium Sulfate, CaSO4)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Pearl (as a biogenic mineral/gemstone)

Calcium Carbonate (mostly Aragonite), CaCO3

Chrysocolla in Matrix

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

Turquoise in Matrix

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

Schist (Micaceous)

Mica Schist

Citrine

SiO2 (Silicon Dioxide)

Fluorite (Rainbow or Multi-colored Fluorite)

Fluorite (Calcium Fluoride - CaF2)

Hematite

Hematite (Fe2O3)

Turquoise and Hematite

CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Fe2O3 (Hematite)

Quartz-veined Sedimentary Rock

Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)

Sandstone (likely with Quartz Veining)

Arenite (primarily SiO2)

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.

Fluorite (Rainbow/Purple Fluorite)

Calcium Fluoride (CaF2)

Slate

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

Granite

Granite

Chrysocolla

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

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)

Schist with Biotite and Quartz

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

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Orthoclase Feldspar

Potassium aluminum silicate (KAlSi3O8)

Limonite (Iron Stone/Gossen)

Limonite (FeO(OH)·nH2O)

Limonite

Limonite (Hydrated iron oxide mixture, FeO(OH)·nH2O)

Granite

Granite

Pebble

Clast (specifically a granule or small pebble)

Turquoise

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

Sulfur on Quartz

Native Sulfur (S8) with Quartz (SiO2)

Garden Quartz (Lodalite)

Silicon Dioxide (SiO2) with mineral inclusions

Gemstone Sand (Mineral Assortment)

Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2) with miscellaneous inclusions

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Granite or Pegmatite with Mica

Granitoid

Banded Gneiss (with possible weathered sulfide or iron staining)

Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides

Chrysocolla

Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)

Jadeite and Mixed Gemstones (Ruby, Sapphire, Emerald)

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

Limonite Concretion (Ironstone)

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Limonite (vibrant yellowish-brown iron oxide)

Limonite (FeO(OH)·nH2O)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)