Igneous And Metamorphic

Mixed Chalcedony and Jasper Bracelet (possibly 'Ocean Jasper' or similar banded variety for brown beads, and blue/grey Chalcedony for the translucent beads)

Chalcedony (SiO2), Jasper (SiO2 with impurities)

Given the appearance, it's likely a fragment of an igneous or metamorphic rock composed of multiple minerals. Without specific diagnostic features, it's difficult to give a common name other than 'crystalline rock fragment'. If pressed to guess based on the granular, somewhat light and dark speckled appearance, it could be a fragment of granite or a related intrusive igneous rock.

As a rock fragment, it does not have a single scientific mineral name; rather, it's a piece of a rock which is a combination of minerals. If it were granite, its main mineral composition would be quartz (SiO2), feldspar (e.g., KAlSi3O8 - orthoclase, (Na,Ca)(Al,Si)4O8 - plagioclase), and mica (e.g., KAl2(AlSi3O10)(OH)2 - muscovite or K(Mg,Fe)3AlSi3O10(OH)2 - biotite), among others.

Mixed Quartz and River Pebbles (Stone Collection)

Mixed assortment containing mainly Silicon Dioxide (SiO2)

Mixed rock and mineral collection

Mixed lithologies; likely quartz, feldspar, basalt, granite, chert, sandstone, and metamorphic rocks

River Rocks (Polished River Pebbles)

Stream-rounded clastic sediments

Limonitic Gossan

Goethite/Limonite aggregate after sulfide

Mica (specimen appears to be Muscovite or Phlogopite)

Phyllosilicate mineral; Muscovite: KAl2(AlSi3O10)(F,OH)2

Mixed Tumbled Gemstones and River Rocks

Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)

Wishing Rock (Quartz Vein in Host Rock)

Silicon dioxide (SiO2) vein in various host rocks

Calcite (or Alabaster, if truly carved)

Calcium Carbonate (CaCO3)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Pyrite (locally known as Fool's Gold)

Iron Sulfide (FeS2)

Magnetite (Lodestone variety)

Magnetite (Fe3O4)

Blue Apatite

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

Likely quartz fragment

Quartz (silicon dioxide, SiO₂), possibly milky quartz or quartz-rich rock

Magnetite

Magnetite (Fe3O4)

Magnetite

Magnetite (Fe3O4)

Pink quartz crystal, possibly rose quartz

Quartz (silicon dioxide, SiO₂), likely pink quartz/rose quartz

Sapphire

Corundum (Al2O3)

Raw Garnet (Hessonite / Spessartine)

Silicate mineral group (X3Y2(SiO4)3)

Muscovite Mica

KAl2(AlSi3O10)(OH)2

Magnetite Ore

Magnetite (Fe3O4)

Milky Quartz

Silicon Dioxide (SiO2)

Nephrite Jade

Nephrite

Zoisite with Hornblende

Zoisite (Ca2Al3(SiO4)3(OH)) with Amphibole inclusions

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Greenschist

Greenschist (containing Chlorite, Actinolite, and Epidote)

Clear Quartz

Silicon Dioxide (SiO2)

Mica

Mica group (often Muscovite or Biotite)

Clear Quartz

SiO2 (Silicon Dioxide)

Apatite

Fluorapatite (Ca5(PO4)3F)

Zoisite with Ruby (Anyolite)

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

Pink Quartz

Silicon Dioxide (SiO2)

Quartz with Epidote

Silicon dioxide (SiO2) with Calcium aluminum iron silicate (Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))

Quartz Heart or Arrowhead Shape

Silicon Dioxide (SiO2)

Magnetite

Iron(II,III) oxide (Fe3O4)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Biotite or Phlogopite Mica

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

Blue Apatite

Calcium Fluorophosphate - Ca5(PO4)3F

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Apatite

Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)

Apatite

Calcium phosphate fluoride/chloride, Ca5(PO4)3(F,Cl,OH)