Mineral With Metamorphic Or Sedimentary Host

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Weathered gold-bearing quartz vein fragment

Quartz (SiO₂) with probable iron oxides and sulfide/mineral inclusions

Tumbled carnelian/chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony or pale carnelian

Quartz Geode

Crystalline Quartz (SiO2) within a sedimentary or volcanic host

Serpentinite

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Ptygmatic Migmatite

Migmatite (consisting of Neosome and Paleosome fractions)

Sandstone with Quartz Vein

Arenite with Crystalline Silica (SiO2)

Quartz Sand Grain / Micro Crystal

Silicon Dioxide (SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Likely galena (lead ore)

Galena, PbS (lead sulfide)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with trace amounts of Chromium/Vanadium

Blue-gray chalcedony (likely common quartz/chert)

Microcrystalline quartz, SiO₂; possibly weathered chert or chalcedony

Quartz pebble / Quartzite

Silicon Dioxide (SiO2)

Emerald (Tumbled Beryl)

Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities

Iron-stained milky quartz vein

Quartz (SiO₂), with iron-oxide/hydroxide staining and minor dark inclusions

Serpentine-rich rock (likely antigorite serpentinite)

Serpentinite, composed mainly of serpentine-group minerals such as antigorite, lizardite, or chrysotile

Shale

Fissile Mudstone

Quartz (Milky/Crystalline)

Silicon Dioxide (SiO2)

Quartz Nodule / Agate Geode

Silicon Dioxide (SiO2)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Tiger's Eye

Silicon Dioxide (SiO2) with Limonite/Goethite pseudomorphs after Crocidolite

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Likely pyrite-bearing rock fragment

Pyrite (FeS₂), possibly in a weathered host rock; identification is uncertain from the image

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Unidentifiable embedded dark fragment

Indeterminate; possibly a dark silicate mineral or lithic inclusion

Milky quartz vein fragment

Quartz (silicon dioxide, SiO₂), likely with iron-oxide staining and minor host rock

Likely quartz-bearing rock or quartz crystal fragment

Quartz, silicon dioxide (SiO₂), possibly with iron-stained matrix

Agate

Silicon Dioxide (SiO2)

Ruby

Corundum (Al2O3) with Chromium traces

Fuchsite in Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) containing Chromium + Quartz (SiO2)

Druzy Quartz on Limestone

Silicon Dioxide (SiO2)

Quartz geode half

Quartz (SiO₂), likely a druzy quartz-lined geode

Quartz (Yellow / Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite inclusions

Sandstone (with Iron Siderite Concretion)

Arenite with Ironstone Concretion (FeCO3)

Lapis Lazuli

Na8[Al6Si6O24]S2 (Lazurite component), a rock composed primarily of Lazurite, Calcite, and Pyrite

Blue kyanite in matrix

Kyanite, Al₂SiO₅

Quartz Crystal Geode / Druzy Cluster

Silicon Dioxide (SiO2)

Carnelian (Chalcedony)

SiO2 (Silicon Dioxide with Iron Oxide inclusions)

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Muscovite mica

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Sandstone Concretion

Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)