Mineral Quiz

Mineral Quiz What makes a mineral unique? Which is not a method by which minerals form? Inorganic processes Water evaporation from a solution Cooling of magma or lava Decrystallization What are the 3 main types of mineral groups? The ocean floor and sea floor consists of a great deal of decomposing hard parts from organisms. What type of rock is created? (Hint: made of calcite and can also be found in caves).

Mineral Quiz Using the image below, choose the best answer. 5. Which lists the minerals in the correct order from softest to hardest? A. Talc, diamond, calcite, feldspar B. Diamond, feldspar, calcite, talc C. Talc, calcite, feldspar, diamond D. Calcite, feldspar, talc, diamond

Igneous Rocks

Igneous Rock Formation Igneous rock: forms when lava or magma cools and minerals crystalize Magma: molten rock below the Earth’s surface Lava: is magma that flows out onto the Earth’s surface The type of igneous rock that forms depends on the composition of the magma. Of all of the compounds present in magma, silica is the most abundant and has the greatest effect on the magma characteristics

TYPES of MAGMA Three types of Magma: 1. Basaltic 2. Andesitic 3. Rhyolitic Type Silica Content Example Location Basaltic 42-52% Hawaiian Islands Andesitic 52-66% Cascade Mountains Rhyolitic More than 66% Yellowstone National park

Classification of Igneous Rocks Classification of igneous rock is based on mineral composition, crystal size, and texture. Two Classifications of Igneous Rocks Intrusive: when magma cools and crystalizes below the Earth’s surface Extrusive: Magma that cools and crystalizes on Earth’s surface

Classification of Igneous Rocks Texture: Size Shape Distribution of the crystals or grains that make up the rock Rhyolite is fine grained while granite is coarse grained The difference in crystal size is because one is intrusive and the other extrusive Rhyolite Granite Obsidian

Classification of Igneous Rocks Crystal size and cooling rates Cools quickly- small crystals Example: rhyolite- extrusive Cools slowly- larger crystals Example: Granite- intrusive

Classification of Igneous Rocks Rock textures provide information about rock’s formation. Porphyritic Rocks: large, well formed crystals surrounded by finer grained crystals of the same mineral or different minerals Vesicular Rocks: Magma contains dissolved gases. If lava is thick enough it traps the gases and holes called vesicles are formed pumice

Igneous Rocks as Resources Veins: a vein is a distinct sheet-like body of crystalized minerals within a rock. Veins form when minerals are deposited through precipitation. Pegmatites: Ores (mineral that contains a valuable substance that can be mined for profit) of rare elements, such as lithium and beryllium.

Igneous Rocks as Resources Kimberlites: minerals formed deep in the crust or in the mantle. Can only from under high pressure. Example: Diamonds

Igneous Rocks as Resources Igneous Rocks in Construction: Interlocking grain texture makes them strong Resistant to weather