Identification of Minerals
Which statement is best supported by the Moh’s Mineral Hardness Scale ◦ A fingernail will scratch
calcite, but not quartz◦ A fingernail will scratch
quartz, but not calcite◦ A piece of glass can be
scratched by quartz, but not by calcite
◦ A piece of glass can be scratched by calcite, but not quartz.
Do Now
Aim: ◦ What are different mineral groups? ◦ How do we identify minerals based on the
reference table? Learning Target:
◦ I can identify minerals by examining their luster, fracture, streak and hardness.
◦ I can discriminate between multiple minerals using a dichotomous key of mineral characteristics
Aim & Learning Target
Definition of a “Mineral”
There are more than 4,000 different minerals on Earth.
Some are quite common, while others are very uncommon, and we don’t use them at all.
So, how do we define minerals?
Mineral: a naturally occurring, nonliving solid, with a definite structure and composition.
We will need to look at this definition a little more closely…
Chemical Composition
Each mineral has a unique chemical composition which makes it different from all other minerals.
Examples: Copper CuGold Au Halite NaClQuartz SiO2
Calcite CaCO3
Corundum Al2O3
Beryl Be3Al2Si6O18
Ruby Al2O3
Diamond C
How do we Identify Them: Pg 16
What are observations that we have of table?
Luster Hardness Cleavage/fracture Common colors Distinguishing characteristics Uses Composition name
It tells us about
They test how well you can use the reference table.
Often on the Regents
example
Graphite use?
1. Find use part of table2. Block out the rest of the table3. Find graphite
example
example
1. Find luster, characteristicspart of table2. Block out the rest3. use process of elimination
example
example
1. Find hardness, dolomite2. Look back at the problem
Answer:
Dichotomous Key Practice
Mineral has: Metallic Luster, Fracture, Colored Streak, and is Hard
Dichotomous Key Practice
Mineral has: Metallic Luster, Fracture, Colored Streak, and is Hard
Dichotomous Key Practice
Mineral has: Non-metallic Luster, cleavage, colored streak, soft __________
Mineral has: Non-metallic Luster, cleavage, colored streak, soft __________
Dichotomous Key Practice
Mineral has Non-metallic luster, fracture, white streak, hard
Mineral has: Non-metallic Luster, cleavage, colored streak, soft __________
Dichotomous Key Practice
Textbook: ◦Pages 50 – 54◦Define the Vocabulary Listed on Page 50◦Complete the Reading strategy listed on
Page 50
Classwork: