Igneous Rock

Diorite (Salt and Pepper Rock)

Diorite

Diorite (Salt and Pepper Rock)

Diorite (comprising Plagioclase Feldspar, Hornblende, and Biotite)

Red Scoria (Lava Rock)

Scoria (Vesicular Basalt)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in Rhyolitic Matrix

Diorite (Salt and Pepper Rock)

Diorite

Diorite (Salt and Pepper Rock)

Phaneritic Plutonic Diorite; chemical composition roughly 52-63% silica (SiO2)

Diorite (Salt and Pepper Rock)

Phaneritic Plutonic Diorite (Plagioclase Feldspar + Amphibole/Biotite)

Scoria (Red Lava Rock)

Scoria

Carnelian Agate

Silicon Dioxide (SiO2) - Variety: Chalcedony

Quartz (specifically Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Quartz (likely tumbled or naturally water-worn)

Quartz (SiO₂ - Silicon Dioxide)

Mineral

Blue Chalcedony

Chalcedony (Silicon Dioxide, SiO2)

Gold Ore in Matrix

Native Gold (Au) in Quartz/Host Rock

Gneiss (Metamorphic Cobble)

Gneiss (High-grade Regional Metamorphic Rock)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Carnelian

Carnelian (Microcrystalline Quartz, SiO2)

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Metamorphic

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

igneous and sedimentary

Epidosite (Epidote-rich rock)

Epidotalite (primarily Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH))

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Gneiss (specifically Pink Gneiss)

Gneiss (high-grade regional metamorphic rock)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Biotite Schist (likely)

Biotite Schist (rock), Biotite (mineral)

Metamorphic

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Granite

Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Igneous

Granite

Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)

Red Granite

Phaneritic Plutonic Felsic Rock (rich in Potassium Feldspar)

Pink Granite

Granite (Phaneritic intrusive rock rich in K-feldspar)

Granite Pebble

Felsic Plutonic Rock (primarily Quartz, Feldspar, and Mica)

Pink Granite (Alkali Feldspar Granite)

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8)

Granite

Phaneritic Plutonic Felsic Rock (KAlSi3O8 + SiO2 + NaAlSi3O8)

Granite (Weathered)

Grano-diorite / Granite (SiO2 rich intrusive rock)