Mineral

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 on Matrix

Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O

Chrysocolla in Matrix

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

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

Calcite

Turquoise in Matrix

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

Red Sandstone

Arenite (Ferruginous Sandstone)

Schist (Micaceous)

Mica Schist

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)

Citrine

SiO2 (Silicon Dioxide)

Amygdaloidal Basalt

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

Slate

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

Granite

Granite

Fluorite (Rainbow or Multi-colored Fluorite)

Fluorite (Calcium Fluoride - CaF2)

Hematite

Hematite (Fe2O3)

Chrysocolla

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

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)

Schist with Biotite and Quartz

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

Granite

Granite

Pebble

Clast (specifically a granule or small pebble)

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 or Pegmatite with Mica

Granitoid

Turquoise

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

Sulfur on Quartz

Native Sulfur (S8) with Quartz (SiO2)

Jadeite and Mixed Gemstones (Ruby, Sapphire, Emerald)

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

Garden Quartz (Lodalite)

Silicon Dioxide (SiO2) with mineral inclusions

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2) with miscellaneous inclusions

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

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)

Banded Gneiss (with possible weathered sulfide or iron staining)

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

Limonite Concretion (Ironstone)

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

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Limonite (vibrant yellowish-brown iron oxide)

Limonite (FeO(OH)·nH2O)