Mineral (Processed Metal)

Quartzite

Quartzite (SiO2)

Pyrite

Iron Pyrite (FeS2)

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)

Quartzite River Cobble

Quartzite (primarily SiO2)

Black Sapphire

Corundum (Al2O3)

Botryoidal Pyrite

Iron Sulfide (FeS2)

Goldstone (Red/Brown)

Aventurine Glass (SiO2 with Copper inclusions)

Emerald

Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.

Quartzite

Quartzite (Primary mineral: Silicon Dioxide, SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Man-made Glass (Tumbled/Shaped)

Amorphous Silicon Dioxide (SiO2) with metal oxide colorants

Red Garnet

Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)

Blue Topaz (facetted in jewelry)

Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)

Pyrite

Pyrite (FeS2)

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Quartz (River Siltstone Quartzite Pebble)

Silicon Dioxide (SiO2)

Imperial Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz with Mineral Inclusions

Green Calcite

Calcite (Calcium Carbonate, CaCO3)

N/A - Image is non-geological

Acrylonitrile Butadiene Styrene (ABS) or Polypropylene (PP)

Granite (weathered pebble)

Granite (plutonic igneous rock)

Rose Quartz

Rose Quartz (SiO₂)

Biotite (Mica)

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

Arsenopyrite with Schist Matrix

Arsenopyrite (FeAsS)

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Chert (Nodular Chert)

Microcrystalline Silica (SiO2)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Nephrite Jade

Nephrite

Tanzanite

Blue-violet Zoisite (Ca2Al3(SiO4)3(OH))

Blue Apatite

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

Aquamarine

Beryl (Be3Al2Si6O18), specifically the blue-green variety

Aquamarine

Beryl (Be3Al2Si6O18), specifically the blue-green variety

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)

Chalcopyrite

Chalcopyrite (CuFeS2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Milky Quartz

Quartz (SiO2)

Ruby

Corundum (Al2O3 with Chromium traces)

Vanadinite

Lead Chlorovanadate, Pb5(VO4)3Cl

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Blue Goldstone

Aventurine Glass

Beryl (Variety Mix)

Be3Al2(Si6O18)

Falcon's Eye (Blue Tiger's Eye)

Pseudomorph of Quartz after Crocidolite (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.