Undetermined

Black faceted gemstone, possibly black spinel or synthetic material

Undetermined from image; candidates include spinel (MgAl₂O₄) or black sapphire (corundum, Al₂O₃)

Colorless faceted gemstone, likely a small diamond or imitation

Undetermined; diamond is carbon (C), but visual appearance alone cannot distinguish it from cubic zirconia or glass

Iron-stained quartz-rich rock (possibly ironstone or ochre-coated quartz)

Undetermined ferruginous rock; yellow-brown coloration likely from goethite and/or limonite (hydrated iron oxides)

Possibly a polished pale-green gemstone cabochon (likely aquamarine or fluorite)

Undetermined from the image; aquamarine is blue-green beryl (Be₃Al₂Si₆O₁₈), while fluorite is CaF₂

Likely iron-rich meteorite fragment

Undetermined stony-iron or iron meteorite; mineralogy may include Fe–Ni metal, troilite, and silicates

Black stone, possibly obsidian or basalt

Undetermined from image; possible volcanic glass (obsidian, SiO₂-rich) or basalt (fine-grained mafic rock)

Likely metallic ore specimen

Undetermined; the silvery, reflective surface may indicate specular hematite (Fe₂O₃), but the image is insufficient for reliable identification.

Blue-gray mineral specimen (possibly sodalite)

Undetermined; appearance may be consistent with sodalite (Na₈Al₆Si₆O₂₄Cl₂), but the image is insufficient for reliable identification

Quartz-bearing rock fragment

Undetermined quartz-rich rock; visible white material is likely quartz (SiO₂), with dark fine-grained host rock

Rock specimen shown in a classroom identification activity

Undetermined; the pictured specimen may be a fine-grained, pinkish rock, but the image does not provide enough detail for a reliable identification

Polished brown-green stone, likely jade or serpentine

Undetermined; possible jadeite (NaAlSi₂O₆), nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), or serpentine-group mineral

Green-tumbled stone, possibly epidote-bearing rock

Undetermined green silicate; possible epidote (Ca₂Al₂Fe³⁺(SiO₄)(Si₂O₇)O(OH)) in a rock matrix

Green cut gemstone, likely synthetic emerald or glass imitation

Undetermined; natural emerald is beryl (Be₃Al₂Si₆O₁₈), while the vivid, very uniform appearance may indicate imitation material

Green cabochon ring stone (likely dyed jade, aventurine, or glass imitation)

Undetermined; possible nephrite jade (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), jadeite (NaAlSi₂O₆), or green aventurine quartz

Mixed rock and mineral specimen collection

Mostly undetermined from the photograph; apparent quartz-rich rocks, sandstone, granite/gneiss, and possibly iron-oxide-bearing specimens

Tumbled dark-green stone, possibly jade or serpentine

Undetermined; candidates include jadeite (NaAlSi₂O₆), nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), or serpentine-group minerals

Likely dark green jasper or serpentinite pebble

Undetermined fine-grained rock; possible serpentine-group mineral (approx. Mg₃Si₂O₅(OH)₄) or jasper (microcrystalline SiO₂)

Tumbled green stone, possibly jade or green aventurine

Undetermined from the image; possibilities include jadeite (NaAlSi₂O₆), nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), or quartz aventurine (SiO₂)

Blue-green copper mineral (possibly chrysocolla or turquoise)

Undetermined from the image; chrysocolla is a hydrated copper silicate, Cu₂H₂O₅Si, while turquoise is CuAl₆(PO₄)₄(OH)₈·4H₂O