Man Made Object (Ring)

Banded Agate (variety of Chalcedony)

Agate (SiO2)

African Turquoise (Jasper)

Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)

Black Onyx

Silicon Dioxide (SiO2) with cryptocrystalline structure

Bloodstone / Heliotrope

Silicon dioxide (SiO2) with inclusions

Amethyst (variety of Quartz)

SiO2 (Silicon Dioxide) with trace iron impurities

Rutilated Quartz

Quartz (SiO2) with Rutile Inclusions (TiO2)

Garnet (likely Almandine or a blend)

Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.

Rose Quartz

Rose Quartz (SiO₂)

Aventurine (likely Green Aventurine)

Aventurine (a variety of quartz, SiO₂, with common inclusions of fuchsite)

Aquamarine

Aquamarine (Beryl variety) - Be3Al2(Si6O18)

Amethyst

Amethyst (a variety of Quartz, SiO2)

Aquamarine

Beryl (Be3Al2Si6O18 with iron impurities)

Diamond

Diamond (C)

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Obsidian

Volcanic glass

Pyrite (or Fool's Gold)

Pyrite (FeS₂)

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Fuchsite

Fuchsite (a variety of Muscovite mica, K(Al,Cr)2(AlSi3O10)(OH)2)

Diamond

Carbon (C), specifically in an isometric crystal system.

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Amethyst

SiO2 (Silicon Dioxide) - a variety of Quartz

Chalcedony

Chalcedony (SiO₂)

Tektite (likely Australite)

Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)

Serpentine Jade (New Jade/Olive Jade)

Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite

Shungite

Carbonaceous rock (primarily amorphous carbon)

Red Jasper or Chert

Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

K2 Jasper (Beads)

Granodiorite with Azurite and Malachite

Turquoise (beads)

Turquoise; CuAl6(PO4)4(OH)8·4H2O

Rhodonite

Manganese Inosilicate (MnSiO3), often with Ca, Fe, Mg, Zn

Peridot

Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)

Garnet Beads

Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)

Gold

Aurum (Au)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Pearls

Aragonite (calcium carbonate) and Conchiolin

Citrine

Quartz (SiO2) - variety Citrine

Rutilated Quartz (beads)

SiO2 with TiO2 inclusions (Titanium Dioxide inclusions within Quartz)

Black Tourmaline (Schorl)

Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))

Amethyst

Quartz (SiO2) with trace iron impurities

Diamond

Diamond (C)

Amethyst

Quartz (SiO2) variety