What are Minerals?
What are minerals?
The building blocks of rocks.
Using your ESRT...list the 5 physical properties we use to identify a mineral.
2. hardness
3. breakage
4. color
5. streak
I am metallic, have a hardness less than 5, a black streak, and have Pb in my composition. What am I?
Galena
How are rocks classified? What are the 3 classifications of rock?
By how they form. They can be igneous, sedimentary or metamorphic.
I am extrusive, glassy and non-vesicular. Who am I?
Obsidian.
Name 2 of the 4 criteria needed to be a mineral.
1. Naturally occurring
2. Inorganic
3. Definite chemical composition
4. Internal atomic structure.
What controls the 5 physical properties of minerals?
I am non-metallic, have a hardness less than 5, have cleavage, and am flexible in thin sheets. Who am I?
Muscovite mica.
How do igneous rocks form?
From the cooling of molten material.
I am intrusive, do not have quartz, am coarse grained. Who am I?
Gabbro
Why is color not a good physical property to use?
Many minerals can be the same color OR one mineral can have many colors.
What is luster? What are the two lusters? How do we find luster in class?
The way light is reflected from a mineral.
The two lusters are metallic and non-metallic.
We find luster by comparing the mineral to the metal legs of our desks. If the mineral shines like the metal legs, it is metallic.
I am metallic, have a hardness more than 5, have fracture, and am magnetic. Who am I?
Magnetite.
How can you tell if you have an extrusive igneous rock?
You cannot see any minerals in the rock.
I am extrusive, intermediate, fine grained and vesicular. Who am I?
Vesicular andesite.
What is streak? How do you find it?
The color of the powdered form of the mineral. Use a streak plate to find it.
What are the two breakages a mineral can have?
Cleavage and Fracture
I non-metallic, have a hardness more than 5, do not have cleavage, and have Fe and Mg in my chemical composition. Who am I?
Olivine
How can you tell if an igneous rock cooled underground?
You will be able to see minerals in the rock.
I am extrusive, have plagioclase, biotite and amphibole, and am vesicular. Who am I?
Scoria
What is the difference between cleavage and fracture?
Cleavage shows itself as parallel lines or breaks in a mineral.
Fracture shows itself as NOT parallel lines or breaks in a mineral.
Does a glassy mineral have a metallic luster?
Not necessarily, not all glasses look like metals. For example, window glass does not look like a metal.
I am non-metallic, have a hardness of either 5.5 or 1, and have a red-brown streak. Who am I?
Hematite.
How is a glass different from a volcanic igneous rock?
A glass has no minerals, a volcanic igneous rock has minerals.
I am intrusive, have lower density, and am very coarse. Who am I?
Pegmatite