1. Name Common Colors Streak Mohs Hardness
A student has an unidentified mineral sample. The mineral is gray and leaves a white streak. The student could scratch the mineral with a copper coin that has a hardness of 3.5, but not with a fingernail that has a hardness of 2.5.
Name
Common Colors
Streak
Mohs Hardness
Graphite
Silver, gray, black
Gray 2
Talc
White, yellow, gray, green
White 1
Orthoclase
White, pink 6
Calcite
Clear, white, gray, brown, yellow, orange, pink, blue, green 3
Based on the information in the table, which mineral does the student have?
A. Graphite C. Orthoclase
B. Talc D. Calcite

2. Which of these were the students most likely observing?
Students were observing a green, odorless mineral, with no visible crystals. The mineral was very soft, with a slick feel. They compared its characteristics to the table below.
Mineral
Most Common Colors
Hardness
Other Common Characteristics
Talc
Gray, green, white, silver 1
Soapy feel
Sulfur
Yellow, yellow-brown
1.5
Greasy feel, mild rotten egg smell
Halite
Colorless, white, pink, yellow 2
Salty taste
Quartz
All colors 7
Six-sided prism-shaded crystal
Which of these were the students most likely observing?
A. Talc C. Halite
B. Sulfur D. Quartz

3. 3. Which of the following substances is a mineral?
A. coal, which is formed with the remains of living things B. fluorite, which is a crystalline solid with the chemical formula CaF2 C. obsidian, which is a volcanic glass and is not crystalline D. brass, which is a metal that is made by humans

4. 4. Which of the following describes a mineral’s streak?
A. Resistance to being scratched
Mineral’s color in powder form
Reflection of light
Mineral breaks in random pieces

5. 5. Which of the following properties of minerals does Mohs scale measure?
A. luster B. hardness C. density D. streak