Sedimentary To Metamorphic

Mixed pebble collection, including likely flint, quartzite, and fossil material

Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil

Jasper

Microcrystalline Quartz (SiO2)

Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

White Quartz Star-cut crystal

Silicon Dioxide (SiO2)

Tumbled orange chalcedony and a gray stone disk

Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate

Milky Quartz

Silicon Dioxide (SiO2)

Likely weathered sandstone or metasandstone

Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)

Raw quartz fragment

Quartz (SiO₂), likely milky or included quartz

Small pale mineral fragment, likely quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Clear calcite cleavage fragment

Calcite (calcium carbonate, CaCO₃)

Weathered iron-stained quartzite or chert nodule

Siliceous rock composed chiefly of microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/minor carbonate minerals

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Pyrite-bearing rock (iron pyrite)

Pyrite, FeS₂, likely disseminated or massive in a host rock

Quartz-rich rock, possibly quartzite

Quartzite (dominantly quartz, SiO₂); identification is provisional from the photo

Polished malachite

Malachite, Cu₂CO₃(OH)₂

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (Red Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly milky quartz or chalcedony

Green calcite (probable)

Calcite, calcium carbonate (CaCO₃)

Fossil shark tooth

Likely fossilized shark tooth, possibly Carcharhinus or Otodus species

Pearl

Pearl; primarily aragonite (CaCO₃) in nacre

Pyrite-bearing rock (likely pyrite-rich quartz or schist)

Pyrite, FeS₂, intergrown with quartz and/or mica-rich matrix

Red Jasper

SiO2 (Silicon Dioxide with Iron inclusions)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Pearl-bearing oyster shell

Nacreous shell, primarily aragonite (CaCO₃), with natural pearls (calcium-carbonate nacre)

Desert rose

Gypsum (selenite) rosette, CaSO₄·2H₂O

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite inclusions

Jasper

Silicon dioxide (SiO2)

Yellow-green serpentine (likely)

Serpentine-group phyllosilicate, commonly lizardite or antigorite; approximate formula Mg₃Si₂O₅(OH)₄

Pearl

Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Limonite Pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2

Weathered quartz-rich rock, likely sandstone or quartzite

Quartz-dominated lithic fragment; probable quartz sandstone (SiO₂)

Banded calcite (likely cave deposit or vein fragment)

Calcite, CaCO₃

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Feldspar-rich Quartzite

Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)

Pearl necklace

Pearl—biogenic calcium carbonate, primarily aragonite (CaCO₃)

Likely anthracite coal fragments

Anthracite; predominantly carbon (C), with minor mineral ash

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Sandstone or Quartzite

Sandstone or Quartzite (SiO2 primarily)

Shale or Slate

Shale (Sedimentary) or Slate (Metamorphic)