Mineral (Biogenic)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Pyrite

Iron Disulfide (FeS2)

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Rhodonite

Rhodonite (Mn, Fe, Mg, Ca)SiO3

Labradorite (Feldspar)

Labradorite: (Ca,Na)(Al,Si)4O8

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Jasper (Green/Yellow Moss Jasper)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Celestine (or Celestite)

Strontium sulfate (SrSO4)

Smoky Quartz with Siderite and Pyrite

Silicon Dioxide (SiO2) with Ferrous Carbonate (FeCO3) and Iron Sulfide (FeS2)

Pink Tourmaline in Quartz Matrix

Elbaite (Na(Li,Al)3Al6(Si6O18)(BO3)3(OH)4) in Quartz (SiO2)

Black Star Diopside

Diopside (CaMgSi2O6) with asterism

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Green Kyanite

Kyanite (Al2SiO5)

Smoky Quartz

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2 with iron impurities)

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

Iron-stained Quartz

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))

Botryoidal Agate

Chalcedony (Silicon Dioxide, SiO2)

Amazonite

Triklinic Potassium Feldspar (KAlSi3O8)

Red Howlite (Dyed)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5) with Red Dye

Rough Emerald/Green Beryl

Beryl (Be3Al2(SiO3)6) with trace amounts of Chromium or Vanadium

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Copper Nugget

Native Copper (Cu)

Green Aventurine

Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Diamond

Diamond (a metastable allotrope of carbon, C)

Quartz (vein quartz)

SiO2 (Silicon Dioxide)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst (Tumbled)

Amethyst (Silicon Dioxide, SiO2 + Fe4+)

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Desert Rose

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

Quartz Geode

Silicon Dioxide (SiO2)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Smoky Quartz

Silicon Dioxide (SiO2)

Ferruginous Quartz

Quartz (Silicon Dioxide) - SiO2 with Iron Oxide inclusions