Mineral and Rock Identification

Granite

IGNEOUS Texture: Coarse Minerals Present: K-Feldspar, Amphibole, Quartz Cooling History: Slow (crystals develop) Composition: Felsic Tectonic Setting: Continental ID: K-Feldspar/Amphibole blend

Gabbro

IGNEOUS Texture: Coarse Minerals Present: Plagioclase Feldspars, Pyroxene Cooling History: Slow (plagio crystals evident) Composition: Mafic Tectonic Setting: Continental ID: Granular crystals in a mafic matrix

Diorite

IGNEOUS Texture: Coarse Minerals Visible: muscovite, plagios Cooling History: Slow Composition: Intermediate Tectonic Setting: Continental ID: Salt and pepper color

Peridotite

IGNEOUS Texture: Coarse Minerals Visible: olivine, pyroxene Cooling History: Slow Composition: Ultra-Mafic Tectonic Setting: Continent Collision zones ID: super dark green with high specific gravity and coarse grains

Basalt

IGNEOUS Texture: Fine-Grained Minerals Visible: fine-grained mafic minerals Cooling History: very quick cooling (fine) Composition: Mafic Tectonic Setting: Ocean Floor/Hot Spot ID: dark, heavy, fine-grained, smooth Uses: asphalt pavement aggregate, railroad ballast, filter stone in drain fields and may other purposes.

Obsidian

IGNEOUS Texture: Glassy Minerals Visible: None Cooling History: Instant Composition: mafic-intermediate Tectonic Setting: continental ID: glassy black, concoidal fractures Uses: tools

Scoria

IGNEOUS Texture: Porous/Vesicular Minerals Present: pyroxenes, micas, andesite, too fine Cooling HIstory: Rapid Cooling with release of gases Composition: Mafic Tectonic Setting: Ocean Hotspot ID: vesicles, reddish-brown color

Porphyritic Andesite

IGNEOUS Texture: Porphyritic Minerals Present: olivines, amphiboles Cooling History: Slow then quick cooling, to get the large crystals surrounded by fine matrix Composition: Intermediate (darker) Tectonic Setting: Ocean-Continent Convergent Boundary/Volcanic island arcs ID: large grains in fine matrix and darker than rhyolite

Porphyritic Rhyolite

IGNEOUS Texture: Porphyritic Minerals Present: quartz, k-feldspars Cooling History: Slow then quick cooling, to get the large crystals surrounded by fine matrix Composition: Felsic (lighter) Tectonic Setting: Continent-Continent Collision Zone ID: large grains in fine matrix and lighter than andesite

Vesicular Basalt

IGNEOUS Texture: porous Cooling History: Quick Cooling Composition: Mafic/Intermediate Tectonic Setting: ocean hotspot ID: dark mafic with vesicles

Pumice

IGNEOUS Texture: porous (aphanitic) Minerals Visible: feldspars, quartz, muscovites Cooling History: Quick cooling of frothy/gassy felsic lava Composition: Felsic Tectonic Setting: Continental Hot Spots ID: super light, porous, light color

Volcanic Breccia

IGNEOUS Texture: pyroclastic Minerals: k-feld matirx, chunks of plagio/muscovite Cooling History: sudden explosion of ash and rock Composition: felsic Tectonic Setting: continental hot spot ID: super chunky

Anthracite Coal

METAMORPHIC Non-Foliated Composition: Carbonaceous material. Texture: Fine Grained, minerals not visible. Black, Shiny, conchoidal fracture.

Biotite Schist

METAMORPHIC , foliated, sparkling crystals of biotite, (mudstone, shale, slate, phyllite), constructive and decorative stone

Mica Schist

METAMORPHIC Composition: Aluminious (Biotite, Muscovite) Texture: coarse-grained, horizontal alignment, foliation of mica sheets Type: Regional Grade: High

Garnet Schist

METAMORPHIC Composition: Aluminious (Biotite, Muscovite, Garnet) Texture: coarse-grained, horizontal alignment, foliation of mica sheets, different from other schists they have garnets Type: Regional Grade: Medium-High

Phyllite

METAMORPHIC Composition: Aluminious (Chlorite, Clay) Texture: fine-grained mica, silky sheen, foliated sheets. Very shiny, reflective in sunlight Type of Meta: Regional Grade: Medium Uses:

Marble

METAMORPHIC Composition: Calcareous Texture: Granoblastic, Coarse Type: Contact/Burial in non-differential stress environment Grade: low-medium Other: reacts with HCL, generally white/pink for our purposes

Dolomitic Marble

METAMORPHIC Composition: Dolmite Texture: Non- Foliated, Non-oriented grains - Med to course grains. Type: Fizzes with dilute HCI only when powdered.

Slate

METAMORPHIC Composition: Mafic Texture: Fine-grained foliation, aligned clay flakes, dull texture, dark black, smooth Type: Regional Grade: Low

Quartzite

METAMORPHIC Composition: quartzo-feldspathic Texture: granoblastic, coarse Type: Contact/BUrial in non-differential stress environment Grade: Can't determine in a quartz/feldspar

Gneiss

METAMORPHIC Composition: quartzo-feldspathic, mafic, or calcareous Texture: Foliated and layered, segregated into light and dark bands (characteristic) Type: Regional/ Dynamothermal Grade: High

GreenStone

METAMORPHIC Olivine & Peridotite made up the fresh basalt have been metamorphosed by high pressure and warm fluids into green minerals—epidote, actinolite or chlorite.The white mineral is aragonite, an alternative crystal form of calcium carbonate (its other form is calcite). Rock of this kind is manufactured in subduction zones and is seldom brought to the surface unchanged.

Breccia

SEDIMENTARY Texture: angular pebbles in fine matrix (only difference between conglomerate) Components: Clastic Transporting Agent: A sudden collision so that the angular bits stick together Environment: Meteor Impact/Glacier Uses: Architectural stones for interior building veneers, tiles, window sills and other decorative applications.

Arkose

SEDIMENTARY Texture: coarse, angular grains, feldspar chunks Components: Clastic Transporting Agent: sediment deposited close to source (poorly sorted), and feldspar isn't given enough time to weather down Environment: alluvial fan Other: red color, chunky

Sandstone

SEDIMENTARY Texture: fine, glittery, sandpaper feel Components: Clastic Transporting Agent: wind, river current Environment: Desert Dunes or Beach Other: can be brown/gray/tan/red in color, grittier than shale and siltstone

Fossiliferous Limestone

SEDIMENTARY Texture: fine-grained matrix, abundant fossils Components: Biogenic Transporting Agent: River Current Environment: shallow marine Other: Fossils + reacts with HCL

Shale

SEDIMENTARY Texture: fine-grained mud, forms sheets Components: clastic Transporting Agent: gravity/current Environment: Deep Marine (bottom mud) Other: can be black, grey, tan, brown, red Uses: Black shales contain organic material that sometimes breaks down to form natural gas or oil. Other shales can be crushed and mixed with water to produce clays that can be made into a variety of useful objects

Coal

SEDIMENTARY Texture: fine-grained, greasy, blocky shape Components: Biogenic Transporting Agent: time, gravity Environment: layers in swamp Other: resinous luster, smell

Conglomerate

SEDIMENTARY Texture: rounded pebbles, coarse-grained Components: Clastic Transporting Agent: rounded sediment weathered before deposition Environment: river deposition, alluvial fan Uses:

Coquina

SEDIMENTARY Texture: super-coarse, made of shells Components: Biogenic Transporting Agent: shells and sand bonding quickly (poorly sorted) Environment: marine environment then buried Other: Reacts with HCL

Siltstone

SEDIMENTARY Texture: super-fine-grained, gritty Components: Clastic Transporting Agent: current Environment: Muddy/Silty Marine

Micritic Limestone

SEDIMENTARY Texture: super-fine-grained, smooth Components: Biogenic Transporting Agent: lithification of lime mud Environment: marine (tiny dead sea-life bits) Other: reacts with HCL

Chert

SEDIMENTARY Texture: super-fine-grained, smooth/glassy, conchoidal fractures Components: Chemical Transporting Agent: precipitated from a water/quartz solution Other: does not react with HCL, lighter color