Mineral (Synthetic)

Sedimentary rock (specifically a concretion or possibly a geode)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock)

Granite / Gneiss Complex

Felsic Plutonic Rock (Granite) or High-grade Metamorphic Rock (Gneiss)

igneous/metamorphic

Fluorite

Calcium Fluoride (CaF2)

Mica Schist

Mica Schist (primarily Muscovite or Biotite-rich sequence)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Sedimentary or Metamorphic (low grade)

Shale or Argillite

Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)

Schist (Diamond Drill Core)

Mica Schist

Sandstone

Arenite (SiO2 with various cementation agents)

Banded Slate (Sedimentary Pebble)

Slate (Metamorphosed Shale or Mudstone)

Petrified Wood

Silicified Wood (SiO2)

Quartzite

Quartzite (primarily SiO2)

Hag Stone

Perforated Sedimentary Rock (typically Limestone or Sandstone)

Mineral/Sedimentary Interface

Gossan with Copper Carbonate (Chrysocolla/Malachite)

Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)

Granite

Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)

Quartzite River Rock

Quartzite (primarily SiO2)

Geode (Unopened)

Silica Concretion / Geode (Formula: SiO2 for quartz internal contents)

Schist

Schist (Crystalline metamorphic rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Schist

Mica Schist

Hemimorphite

Hemimorphite (Zn4Si2O7(OH)2·H2O)

Rose Quartz

Silicon Dioxide (SiO2) with traces of titanium, iron, or manganese

Manganese Dendrite on Siltstone

Manganese Oxide (pyrolusite or psilomelane) Dendrites

mineral/sedimentary

Pink Halite (Himalayan Salt)

Halite (Sodium Chloride, NaCl)

Diamond

Carbon (C)

Granite Pebble

Granitoid (Felsic Plutonic Rock)

Mineral (variety of Chalcedony)

Green Aventurine

Aventurine (variety of Quartz - SiO2)

Mineral_Rock

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and mineral inclusions

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Granite

Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)

Diorite

Diorite (Intermediate Plutonic Rock)

Diorite

Diorite (Intermediate intrusive igneous rock)

Petoskey Stone

Hexagonaria percarinata

Sedimentary

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (composed mostly of SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Diamond

Carbon (C)

Magnetite

Magnetite (Fe3O4)

Quartz with Hematite Staining

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) inclusions

Milky Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Gold Quartz (Auriferous Quartz)

Silicon Dioxide (SiO2) with trace Gold (Au) and Iron Oxides