Geology Lab 1 Final

Biotite

• Features: Soft black mica, basal cleavage making thin sheets (often flexible).

Calcite

• Features: Soft rhombohedral cleavage white (sometimes clear) that will fizz under a drop of acid.

Galena

• Features: Metallic luster, silver gray, very high density, with a black streak.

Gypsum

• Features: Soft, H=2, scratched with fingernail on the larger cleavage plane.

Halite

• Features: Soft, cubic cleavage, salty taste.

K-feldspar

• Features: Hard, H=6, will leave white streak, 2-cleavage planes at 90-degrees, often pink to orange color.

Muscovite

• Features: The white to silver colored mica, basalt cleavage making thin flexible sheets.

Pyrite

• Features: Gold metallic luster with a black streak (fool’s gold).

Quartz

• Features: Hard, H=7, has a conchoid fracture often in elongated, six-sided (hexagonal) crystals.

Geology Flashcards: Rocks

Basalt (Igneous)

• Features: Mafic + aphanitic.

Granite (Igneous)

• Features: Felsic + phaneritic.

Obsidian (Igneous)

• Features: Dark color + glassy luster + conchoidal fracture.

Scoria (Igneous)

• Features: Mafic + highly vesicular.

Slate (Metamorphic)

• Features: Foliated + invisible grain size.

Schist (Metamorphic)

• Features: Foliated + coarse grain size.

Gneiss (Metamorphic)

• Features: Segregation banding.

Marble (Metamorphic)

• Features: Crystalline (nonfoliated) + Calcite.

Quartzite (Metamorphic)

• Features: Crystalline (nonfoliated) + Quartz.

Breccia (Sedimentary)

• Features: Gravel-size clasts with sharp, angular corners for shape of gravel fragments.

Conglomerate (Sedimentary)

• Features: Gravel-size clasts with rounded shape for gravel fragments.

Arkose (Sedimentary)

• Features: A sandstone with abundant K-feldspar grain, often with hematite (red) cement.

Lithic Sandstone (Sedimentary)

• Features: Sand-sized grains of rock fragments (often pieces of basalt), gray in color.

Quartz Sandstone (Sedimentary)

• Features: Sand-sized grains made of quartz.

Shale (Sedimentary)

• Features: Mud-sized grains (smooth) in a fissile texture.

Limestone (Sedimentary)

• Features: Made of crystalline calcite (fizz), soft.

Chert (Sedimentary)

• Features: Made of microcrystalline quartz, light color, hard (scratch glass), has conchoidal fracture.

Rock Salt (Sedimentary)

• Features: Made of halite, crystalline, salty taste.

Coal (Sedimentary)

• Features: Black, Very low density, marks on paper.

Geology Flashcards: Concepts

Gradient

• Definition: The steepness or slope of a stream; (Vertical Drop / Horizontal Distance).

Sinuosity

• Definition: How much a river curves; (Channel Length / Straight Line Distance).

Discharge (Q)

• Definition: The volume of water flowing past a point; (Area x Velocity).

Epicenter Location

• Process: Using 3 travel-time curves from different stations to triangulate the exact location.

Richter Magnitude

• Definition: A scale of earthquake size based on the maximum amplitude of seismograph waves.