Download Lab Properties 2

Name _______________________________________________
Teacher ______________________
Date: / /
per._____
LAB # _____
TITLE: Earth’s Minerals
OBJECTIVE: Of some 4,000 known minerals, only about a dozen called “common rockforming minerals” make up Earth’s crust. They are identified in the field by a few simple
physical tests and observations. This is possible because the physical properties are
remarkably constant in a mineral no matter how old it is or where it was formed. In addition to
physical tests, there are also some useful diagnostic chemical tests by which minerals can be
further identified. In this lab, we will identify some of the most commonly found minerals on the
planet, including those you could just find on your way to school.
VOCABULARY: mineral, luster, streak, hardness, cleavage, fracture, organic, inorganic,
clastic, composition, and monominerallic
MATERIALS: various minerals, streak plates, penny, rock hammer, steel nail, magnifying lens,
glass plate, bottle dropper, dilute hydrochloric acid, and paper towels
PROCEDURE:
1. Determine the properties for each of the minerals by using the tools for appropriate
testing. Record your results on the data table. Use the Mineral Identification Chart
below.
2. Use the Properties of Common Minerals Chart and the Mineral Identification Chart
and identify each mineral sample by name.
QUESTIONS:
1. What is the distinction between fracture and cleavage?
2. Why is color alone not a reliable means of identifying a mineral?
3. Why is streak a more reliable property than color in mineral identification?
4. What mineral(s) is usually identified by using the acid test?
CONCLUSION: Explain how minerals are identified, include two additional methods not used
in this lab.
ABOVE & BEYOND: Research any four minerals and list their properties and uses, include a
picture of it. Do not research any of the minerals used in the lab.
MINERAL IDENTIFICATION CHARTS
FRACTURE
Smooth or rough curved break
Fibrous or splintery break
Rough surface with sharp edges
Rough surface
Conchoidal
Splintery
Hackley
Uneven
CLEAVAGE
3 or more good to perfect planes
2 good to perfect planes
one good to perfect plane
1,2, or more imperfect planes
No planes
Perfect
Parallel
Basal
Poor
None
LUSTER
Golden, coppery or silvery reflection
A somewhat metallic reflection
Adamantine or vitreous reflection
Oily, greasy silky or resinous reflection
Earthy, or non-reflective surface
Metallic
Submetallic
Glassy
Waxy
Dull
*Quartz is the hardest common mineral.
HARDNESS SCALE
Simple Test
Fingernail scratches it easily
Fingernail scratches it
Copper penny just scratches it
Steel nail scratches it easily
Steel nail scratches it
Steel nail won’t scratch it
It scratches window glass
Quartz
It scratches steel and hard glass
Topaz
Harder than any common mineral
(scratches quartz)
Corundum It scratches topaz
Diamond
Hardest of all minerals
Mohs Hardness ScaleMineral
1
Talc
2
Gypsum
3
Calcite
4
Fluorite
5
Apatite
6
Feldspar
7*
8
9
10