Mineral Specimen

Weathered quartz-rich rock fragment

Indeterminate; likely quartz-bearing silicate rock

Epidote

Ca2(Al, Fe)3(SiO4)3(OH)

Ruby / Red Tourmaline

Corundum (Al2O3) or Elbaite (Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)4)

Likely weathered metallic mineral or slag fragment

Indeterminate; possibly iron-rich sulfide/oxide material or industrial slag

Likely quartz-rich stone or pale feldspar fragment

Indeterminate; possibly quartz (SiO₂) or feldspar (KAlSi₃O₈–NaAlSi₃O₈)

Quartz on Feldspar

Silicon Dioxide (SiO2) with Potassium Feldspar (KAlSi3O8)

Botryoidal Goethite

Goethite (α-Fe3+O(OH))

Limonite pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O

Quartz Druzy Geode Fragment

Silicon Dioxide (SiO2)

Small quartz-rich rock fragment (tentative)

Likely quartz (SiO₂) with possible feldspar or carbonate inclusions

Amethyst jewelry centerpiece

Amethyst, purple quartz (SiO₂), likely set with colorless diamonds or other gems

Quartz (Druzy) on Matrix

Silicon Dioxide (SiO2)

Sapphirine in Matrix

Sapphirine (Mg,Al)8(Al,Si)6O20

Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Desert Rose

Gypsum (CaSO4·2H2O) or Barite (BaSO4) inclusions in sand

Tumbled amethyst

Quartz, purple variety; SiO₂

Tumbled carnelian/chalcedony

Orange chalcedony, microcrystalline quartz (SiO₂), likely iron-oxide-bearing

Native Copper

Copper (Cu)

Quartz

Silicon Dioxide (SiO2)

Microcline Feldspar

KAlSi3O8

Sphalerite

Zinc Sulfide (ZnS)

Eudialyte with Syenite

Eudialyte: Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2

Hematite

Iron(III) oxide (Fe2O3)

Quartz (Druzy)

Silicon Dioxide (SiO2)

Limonite/Goethite Gossan

FeO(OH)·nH2O (Hydrated iron oxide)

Weathered iron-rich rock fragment

Likely limonite/goethite-bearing rock, possibly altered pyrite or mica schist

Possible weathered iron-rich rock or slag fragment

Indeterminate; likely limonite/goethite-bearing material, possibly iron slag

Weathered iron-rich rock, possibly laterite or limonite-bearing stone

Hydrated iron oxides/hydroxides, chiefly limonite-goethite mixture; exact identification requires testing

Rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Amazonite

Amazonite (Microcline variant: KAlSi3O8)

Tumbled aventurine quartz

Quartz (SiO₂), likely green-gray aventurine with mica or hematite inclusions

Azurite in Matrix

Azurite (Cu3(CO3)2(OH)2) in Rhyolite or Sandstone matrix

Amethyst Cluster

Silicon Dioxide (SiO2) with iron impurities

Amethyst Geode

Amethyst (Silicon Dioxide, SiO2)

Chert (Jasper/Chalcedony mix)

Microcrystalline Quartz (SiO2)

Hypersthene

Hypersthene ((Mg,Fe)SiO3)

Chrysocolla

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

Red Jasper with Quartz

Microcrystalline Quartz (SiO2)

Chalcedony

Chalcedony (SiO2)

Celestite Geode

Strontium Sulfate (SrSO4)

Hematite Pebble

Hematite (Fe2O3)