any coherent, naturally occurring, substance generally composed of minerals
any rock type can become any other rock type
three rock types
igneous, sedimentary, and metamorphic
beach sand, molten lava, concrete
a substance that is naturally occurring, inorganic, has a definite chemical composition, is a crystalline
tools for the identification of minerals
hardness, luster, color, streak, cleavage, fracture, cleavage vs. crystal form, and other miscellaneous properties
measure of the resistance of a mineral to scratching (non breakage)
Mohs Hardness Scale
softness = 1 and hardness = 10
hardness of a ceramic tile
between 5 and 6
the color of the powdery residue of a mineral left behind when it is dragged across an unglazed porcelain plate (hardness of porcelain plate = 6); streak is the same color regardless of the presence or absence of impurities on a mineral
streak provides the intrinsic color of a mineral; color is a poor identifier (sulfur is normally yellow and pyrite is normally brassy)
the way a mineral reflects light
looks like a metal such as gold, silver, iron etc.
vitreous, pearly, resinous (glazed), earthy
breakage of a mineral along a flat plane of weakness
uneven (non-planar) breakage
obsidian or quartz; breaks along a surface marked by concentric circles
like splinter in a wood
a catch-all term for non-diagnostic; non-planar breakage
how a mineral grows; of a crystal grows out of an apparent flat cleavage face, the face isn't cleavage - it is crystal form
mineral classification: metals
combined with oxygen = oxide minerals; combined with sulfur = sulfide minerals; not combined with other elements = native (native gold, native copper, etc.)
mineral classification: silicates
Si is an important ingredient
(Fe and Mg); dark and dense
Please allow access to your computer’s microphone to use Voice Recording.
We can’t access your microphone!
Click the icon above to update your browser permissions above and try again
Reload the page to try again!
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Your microphone is muted
For help fixing this issue, see this FAQ.