PowerPoint Review of Geology

INCD 140

Professor Pan

BASALT: dark colored, fine-grained extrusive rock, most widespread of all the igneous rocks, volcanic in origin

CALCITE: pure calcium carbonate (CaCO3), found in limestone and marble, cementing agent in sedimentary rocks, crystals formed from pure calcite are in the form of a perfect rhomboid, perfect cleavage in

three directions, hardness of 2, forms stalactites and stalagmites

CHERT: very hard sedimentary rock, light gray to dark gray in color, fossilized ancient sea animals, flint is a very dark form of chert, breaks

with conchoidal fractures, arrowheads, spear heads, and knives.

COAL: Organic sedimentary rocks form from the build up and decay of plant and animal material, usually forms in swamp regions, the longer

and deeper that coal is buried makes it of higher quality, peat then lignite then bituminous and finally anthracite

CONGLOMERATE: clastic sedimentary rock, forms from the cementing of rounded cobble and pebble sized rock fragments, formed by river movement or ocean wave action, silica, calcite, or iron oxides

act as cementing agents

GABBRO: dark-colored, coarse-grained, intrusive igneous rock, very similar to basalt in its mineral make up, composed mostly of

plagioclase feldspar with smaller amounts of pyroxene and olivine

GALENA: an iron sulfide, the main source of lead, occurs in cubic crystals, has a metallic luster, a black to dark gray color and streak, a

hardness of about 2.5

GNEISS: a high grade metamorphic rock, coarser than schist, has distinct banding with alternating layers that are composed of different

minerals used as paving and building stone

GRAPHITE: pure carbon, a hardness between 1 and 2, has a black streak, formed by the metamorphism of plant remains, used for "lead"

in pencils, and in the paint industry

HALITE: aka table salt, forms where brackish waters dry up, occurs in crystal form, usually colorless, has perfect cleavage, hardness of 2.5

HEMATITE: most important source of iron ore, has a red or black color, a red streak, has a metallic or earthy luster, a hardness of 5, no

cleavage and breaks with an uneven fracture

LIMESTONE: most abundant of the non-clastic sedimentary rocks, produced from the mineral calcite and sediment, chalk is a type of

limestone that is made up of very small single-celled organisms, easily dissolved by acids, will fizz in contact with vinegar

MAGNETITE: aka lodestone, a mineral with high iron content, a black or brownish-red color, a black streak, a hardness of 6, naturally

magnetic

MARBLE: metamorphosed limestone or dolomite, many color variances due to the impurities present at formation, can be polished, a building material, making sink tops, bathtubs, and a carving stone for

artists

OBSIDIAN: very shiny natural volcanic glass, conchoidal fracture, produced when lava cools very quickly, usually black or a very dark

green, but it can also be found in an almost clear form, used for arrowheads, knives, spearheads, and cutting tools of all kinds, and as

a scalpel by doctors in very sensitive eye operations

PYRITE: aka iron sulfide, aka “fools gold” is one of the most common minerals on the Earth's surface, a green to dark gray streak, a

hardness of 6.5, and cubic or not distinct cleavage

QUARTZ: a common mineral, can be broken or weathered into the tiny pieces of sand, a hardness of 7, can be colored yellow, milky white,

rose, smoky (brown or black), and purple, caused by impurities during formation, used in producing optical instruments, electrical devices,

and to make sandpaper and grinding tools

QUARTZITE: composed of sandstone that has been metamorphosed. Quartzite is much harder than the parent rock, sandstone, formed from

sandstone that has come into contact with deeply buried magmas

SANDSTONE: a clastic sedimentary rock, forms from the cementing together of sand sized grains, Quartz is the most abundant mineral that

forms sandstone

SLATE: fine-grained metamorphic rock with perfect cleavage that allows it to split into thin sheets, has a light to dark brown streak,

headstones or grave markers, used for chalk boards

TALC: aka soapstone, has perfect cleavage, a greasy or soapy feel, hardness of 1, used by artists for sculptures, to make crayons, paint,

paper, and soap

INFORMATION

I am currently enrolled in GEO 120, an introductory course in geology with Professor Becker here at TCNJ. I did this as a review of some of the materials.

Sources include class notes, and a website that made inputting the data easier:

http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/lesson.html