Science - Classifying Rocks Flashcards

Earth's Crust Composition

• Earth's crust is primarily composed of rock.

Rock Classification

• Rocks are classified based on texture, mineral composition, and color.

Composition of Rocks

• Rocks consist of minerals, cooled magma, and can be both inorganic and organic, with silica being a common component.

Granite Components

• Granite typically contains quartz, feldspar, mica, and hornblende.

Rock Identification

• Color alone is not sufficient for identifying most rocks; additional features are required.

Definition of Texture

• Texture refers to the look and feel of a rock's surface.

Grains in Rocks

• Grains are the particles of minerals and other rocks that constitute a rock's structure.

Grains and Texture Connection

• The grains of a rock contribute significantly to its overall texture.

Coarse Grain Misconception

• The term "coarse grain" is not used to describe a rock's grain pattern.

Grain Shape Description

• The shape of a rock's crystals and fragments of other rocks characterizes its grain shape, especially in granite.

Conglomerate Grain Description

• Grain characteristics in conglomerate include fineness, shape of crystals, size, and fragments.

Gneiss Grain Pattern

• Gneiss features a banded appearance with varying colors, resembling stacked pancakes.

Geologist Classification Criteria

• Geologists utilize texture, streak, and color for classifying rocks.

Major Rock Groups

• The three main groups of rocks are igneous, sedimentary, and metamorphic.

Formation of Igneous Rocks

• Igneous rocks are formed from molten rock material.

Formation of Sedimentary Rocks

• Sedimentary rocks occur when particles are pressed together and cemented.

Formation of Metamorphic Rocks

• Metamorphic rocks arise when existing rocks undergo transformations due to heat and pressure.

Metamorphic Rock Formation Location

• Contrary to belief, most metamorphic rocks form deep beneath the Earth's surface, not close to it.

Texture Reiteration

• The texture of a rock encompasses its surface aesthetics and tactile qualities.

Definition of Grains

• The particles that form a rock are collectively referred to as grains.

Rock-Forming Minerals

• There are 20 key minerals recognized as the primary constituents of Earth's crust rocks.