a) naturally occurring
b) homogeneous (same) inorganic (non-living) solid substance
c) definite chemical composition
d) crystalline structure
Mohs Scale of Hardness: We use different tools to determine a mineral's hardness: fingernail, penny, nail, and a few key minerals. Check the scale.
Color - Color can be used to identify minerals, but don't use only the color to identify the mineral. Alot of minerals might have the same color amongst them.
Streak test- Streak a metal across a tile to observe the true color the mineral leaves behind. More reliable than color of the mineral.
Cleavage and fracture-
Cleavage is the way a mineral breaks. Many minerals break along flat planes, or cleavages - some in only one direction, others in two directions, and some in three directions, or more. Ex: Mica, Feldspar, Calcite, and Fluorite. Tricky one is graphite, you need a hand lens to see the cleavages of this minerals.
Fracture is breakage that is not flat, mostly a jagged edges. Best example is quartz.
Luster- Luster is basically the way a mineral reflects light. The three major types of luster are metallic, glassy, and earthy (dull). I like to just describe luster as metallic or non-metallic.
a) Magnetism is a distinctive property in a few minerals. Best example: Magnetite
b) Taste is a distinctive tastes. Best example: Halite and other evaporite.
c) Fizz is made when an effervescent reaction of certain carbonate minerals to the HCl test. Example: Limestone
d) Heft is how heavy a mineral feels. Density comes to mind. Remember density is the relation of mass and volume of an object.
Igneous rocks are formed from molten rock materials.
a) Intrusive - formed below Earth's surface. Crystals grow large, cools slowly.
Diorite Gabbro Granite Pegmatite
b) Extrusive - formed on or above Earth's surface. Crystals are small, cools rapidly.
Andesite Basalt Obsidian Pumice
Sedimentary rocks are formed from pieces of broken rock, shells, mineral grains, and other materials.
a) Clastic (detrital)- formed from mechanical weathered debris (grains from other rocks)
Breccia Conglomerate Sandstone Shale
b) Chemical - formed when dissolved materials precipitate from solution.
Iron Ore Limestone (some) Rock Salt
c) Organic - formed from the accumulation of plants or animal debris.
Coal Limestone (coquina) -shells Limestone (chalk)
Metamorphic rocks are rocks that have been changed by heat, pressure, and chemical process usually while they are buried below Earth's surface.
These rocks have been changed in their texture and chemical composition.
a) Foliated - layered or banded appearance caused by extreme heat and pressure. (increase heat and pressure can change the rock into another rock)
Parent rock of the following is a shale.(Parent rock: shale changes to slate, phyllite, schist, and gneiss)
With enough heat and pressure can change a granite to a gneiss.
Slate can turn into a Phyllite
can turn into a Schist can turn into a Gneiss (banded)
b) Non-foliated - do not have a layered appearance.
Parent: Limestone into Marble Parent: Sandstone into Quartizite
Video of the rock types:
Rock Cycle - A great way to show the journey of three rock types.
Interactive rock cycle: http://www.learner.org/interactives/rockcycle/diagram.html
Bonus: Look at the bottom of this page for subpages (1) and click on the
link to find out more.
Needs to be turned in by beginning of class: October 18th