Metamorphic Or Igneous (Context Dependent)

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Ferruginous Sandstone (Ironstone)

Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))

River Cobble (Conglomerate context)

Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)

Chert (Nodule)

Cryptocrystalline Silica (SiO2)

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

Ferruginous Conglomerate

Ferruginous Conglomerate (Clastic Sedimentary Rock)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Magnetite

Magnetite (Fe3O4)

Bornite

Bornite (Cu5FeS4)

Nephrite Jade

Nephrite

Biotite or Phlogopite Mica

K(Mg,Fe)3(AlSi3O10)(F,OH)2

Sapphire (Corundum variety)

Sapphire (Al₂O₃)

Chert (Flint)

Silicon Dioxide (SiO2)

Blue Apatite

Apatite-(CaF), Ca5(PO4)3F (Calcium Fluorophosphate)

Chert (often called Flint in this context)

Silicon Dioxide (SiO2)

Chert (often called Flint in this context)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Rutilated Quartz

SiO2 with TiO2 inclusions (Rutile)

Zoisite with Ruby (Anyolite)

Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Magnetite

Magnetite (Iron(II,III) oxide, Fe3O4)

Epidote

{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Opalite

Synthetic Glass, SiO2 base with metallic inclusions

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Yellow Sapphire or Citrine

Al2O3 (Corundum) or SiO2 (Quartz)

Blue Apatite

Apatite, Ca5(PO4)3(F,Cl,OH)

Gold (Elemental Metal)

Gold (Au)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Magnetite Orthorthotropic Rock

Magnetite (Fe3O4)

Magnetite

Iron(II,III) oxide (Fe3O4)

Milky Quartz

Silicon Dioxide (SiO2)

Rhodonite, Gray Moonstone, and White Feldspar Mix

Multiple: MnSiO3 (Rhodonite), (K,Na)AlSi3O8 (Feldspar/Moonstone)

White Sapphire

Corundum (Al2O3)

Blue Calcite

Calcium Carbonate (CaCO3)

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Milky Quartz

Silicon Dioxide (SiO2)

Biotite (Black Mica)

K(Mg,Fe)3AlSi3O10(OH,F)2

Fluorite

Fluorite (Calcium Fluoride - CaF2)

Shale creek bed

Shale (fine-grained clastic sedimentary rock)

Magnetite (Small Granule)

Magnetite (Fe3O4)