Metamorphic Or Sedimentary Depending On Local Grade

Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Anthracite Coal

Anthracite (Highly Metamorphosed Coal)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Rhodonite

Rhodonite (MnSiO3)

Granite Gneiss

Gneiss (high-grade metamorphic rock)

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)

Greenschist

Greenschist (Major minerals include Chlorite, Actinolite, and Epidote)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Jade (Jadeite/Nephrite)

NaAlSi2O6 (Jadeite) / Ca2(Mg,Fe)5Si8O22(OH)2 (Nephrite)

Slate with Red Sandstone Landscaping Rock

Foliated Pelitic Metamorphic Rock (Slate) and Ferruginous Sandstone

Rhodonite

Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn,Fe,Mg,Ca)SiO3

Epidote (likely Pistacite in Epidosite rock)

Epidote: Ca2(Al,Fe)3(SiO4)3(OH)

Gneiss

Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)

Green Slate (Greenstone)

Metamorphic shale (varied composition)

Slate

Foliated Metamorphic Rock

Conglomerate (Puddingstone)

Conglomerate (specifically, clastic sedimentary rock)

Chlorite (Small Flakes/Sand)

Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)

Slate with Quartz

Low-grade Metamorphic Slate with SiO2 inclusions

Schist

Mica Schist

Unakite

Epidotized Granite

Ruby (Corundum)

Corundum (Aluminum Oxide) with chromium trace elements, Al2O3

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Banded Agate (with possible Chalcedony layers)

Silicon dioxide (SiO2)

Anthracite Coal

Anthracite

Yellow Diamond (Faceted)

Diamond (C - Pure Carbon)

Quartzite

Quartzite (primarily SiO₂)

Pyrite

Iron Sulfide (FeS2)

Corundum (Ruby Variety)

Corundum (Al2O3)

Unakite

Epidotized Granite

Epidote

Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Quartzite with Chlorite/Epidote

Metamorphosed Quartzite (SiO2)

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

Graphite

Graphite (Carbon, C)

Anthracite Coal

Anthracite (Carbon Content: 86%-97%)

Schist

Mica Schist

Greenschist (Chlorite Schist)

Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)

Slate with Pyrite Inclusions

Foliated Metamorphic Rock (with Iron Sulfide FE-S2)

Schist

Mica Schist

Diamond

Carbon (C)

Rough Emerald in Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)