Mineral Based Composite

Jasper / Quartz Pebble

Silicon Dioxide (SiO2) with microcrystalline impurities

Fuchsite Schist

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist

Beryl (Aquamarine) in Matrix with Schorl

Be3Al2Si6O18 (Beryl) with NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

Granite

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

Granitic Pegmatite (Muscovite and Quartz)

Pegmatite (KAl2(AlSi3O10)(OH)2 / SiO2)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Lepidolite

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

Tumbled orbicular granite or granitic gneiss

Granite, chiefly quartz–feldspar–biotite/amphibole; exact variety uncertain from the image

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Sandstone (Lithic Arenite)

Clastic Sedimentary Rock (primarily SiO2)

Sandstone nugget

Arenite (primarily Quartz SiO2)

Sandstone (Quartz-rich)

Arenite

Sandstone (with minor quartz and possible clay components)

Clastic Sedimentary Rock (SiO2 dominated)

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions

Basalt Pebble with Vesicles

Vesicular Basalt

Granitoid (Granite/Gneiss mix)

Phaneritic Felsic Igneous Rock

Emerald in Matrix

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Quartz (Iron-Stained / Ferruginous Quartz)

Silicon Dioxide (SiO2)

Bloodstone

Chalcedony (Variety Heliotrope), SiO2

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Granite

Granite

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Quartz / Common Gravel

Silicon Dioxide (SiO2)

Serafina (Serafinite / Clinochlore)

Clinochlore (Mg5Al)(AlSi3O10)(OH)8

Glauconitic Sanstone (Glauconite)

Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Mica-rich Schist fragment

Mica Schist

Sandstone / Weathered Chert

Silicon Dioxide (SiO2) / Quartz-rich Clastic Rock

Conglomerate

Conglomerate (SiO2 matrix with various silicate clasts)

Chert with Quartz Veining

Microcrystalline silica (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Blue Topaz (specifically London Blue or Swiss Blue based on color saturation)

Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Lepidolite with Rubellite Tourmaline

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lepidolite mica)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Beryl (Aquamarine variety)

Beryllium Aluminum Cyclosilicate (Be3Al2Si6O18)

Graphite

Graphite (Native Carbon, C)

Dragon Blood Jasper

Epidote with Red Jasper (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH))

Granitic Sand

Detrital sediment (predominantly Quartz, Feldspar, and Mica)

River Cobble (likely Basalt or Greenstone)

Mafic Igneous Rock (with possible chloritic alteration)