Granite
Course-grained intrusive igneous rock
igneous
Category
Not A Natural Rock (Man Made Composite)
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
Diabase (also known as Dolerite)
Diabase / Dolerite
igneous
Red Sandstone
Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)
sedimentary
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Mineral
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Igneous
Serpentine Jade (New Jade/Olive Jade)
Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite
Mineral
Granite
Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
sedimentary
Agate (Bead Form)
Agate (Cryptocrystalline Quartz, SiO2)
mineral
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
mineral
Citrine
Quartz (SiO₂)
mineral
White Quartz
Quartz (SiO2)
Mineral
Tufa (Vesicular Limestone)
Tufa (form of Calcium Carbonate, CaCO3)
sedimentary
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
sedimentary
Chert (specifically Flint)
Microcrystalline quartz (SiO2)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Basalt
Extrusive Mafic Igneous Rock
igneous
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Plagioclase Feldspar (specifically Albite/Oligoclase)
(Na,Ca)(Si,Al)4O8
mineral
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Carnelian
Carnelian (Silicon Dioxide - SiO2 with iron oxide impurities)
mineral
Quartz Pebble (Chalcedony/Agate)
Silicon Dioxide (SiO2)
Mineral
Sandstone (Quartzite Pebble)
Arenite / Metamorphosed Sandstone (SiO2)
sedimentary
Granodiorite
Phaneritic intrusive igneous rock (Granodiorite)
igneous
Pink Feldspar
Orthoclase (KAlSi3O8) or Microcline
mineral
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Diamond (set in jewelry)
Diamond (Carbon, C)
mineral
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Blue Topaz (specifically London Blue or Swiss Blue based on color saturation)
Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)
mineral
Granite with Mafic Inclusions
Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)
igneous
Basalt with Quartz/Epidote Vein
Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)
igneous
Basalt (River Pebble)
Basalt (dominated by Plagioclase Feldspar and Pyroxene)
igneous
Quartz Vein in Host Rock (Likely Slate or Shale)
Hydrothermal Quartz (SiO2) in Pelitic host rock
metamorphic
Citrine Quartz
Silicon Dioxide (SiO2) - Ferric Iron impurities
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Dyed Howlite (simulating Lavender/Purple Jade or Charoite)
Howlite: Ca2B5SiO9(OH)5 (when natural)
Mineral
Carnelian
Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO2)
Mineral (variety of Chalcedony)
Granitoid (Granitic Rock)
Granitoid (Quartzo-feldspathic plutonic rock)
igneous
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary