Rock Cycle - Minerals (2A)

  • Reviewing how to use a magnifying glass.
  • Comparing different minerals.
  • dull
  • scratch
  • shiny

Students use magnifying glasses to compare different minerals.


A mineral is a crystalline, inorganic, naturally occurring combination of one or more elements. Observation is a key skill in identifying minerals. This ability involves developing logical thought processes. Learning minerals and mineral identification properties is very difficult without hands-on activities, but is very easy when children can explore and touch minerals. This lab helps students develop those skills. Identifying minerals is important because minerals make up rocks.

The observational lesson prior to this lab can help students use their senses to become familiar with the different minerals. Some minerals like halite (salt) can be identified by their taste, while others are identified by their hardness (quartz). The more students see and feel minerals, the easier it is to remember them.

  1. Demonstrate how to use a magnifying glass. The students should hold the magnifying glass close to their face with one hand, and then move the specimen back and forth with the other hand until in comes into focus. Allow the students to experiment briefly, looking at their hands or any other available objects.
  2. Explain to the students that today they will be looking at minerals and trying to determine some of their characteristics. Review the different characteristics that the students may see when they examine the minerals. These properties include: color, hardness, luster (glassy or metallic), crystal shape (see examples below) or unusual properties (ulexite and calcite).

    Students should  examine each of the specimens. They should use the magnifying glass to look at each specimen closely, as well as their other senses. Stress with students that learning about minerals includes both examining and thinking.

  3. As the students examine each specimen, they should circle the characteristic that is most like the mineral in the workbook. Review the correct answers after the students complete their lab. Use the following information to help guide your remarks.

QUARTZ is made up of silicon and oxygen. You might want to point silicon and oxygen on the periodic  characteristic is that quartz is very hard. It is so hard that a steel knife cannot scratch it.

GYPSUM is made of calcium, sulfur and oxygen. Unlike quartz, it is very soft; a gypsum crystal can be scratched by a fingernail. Gypsum is used in making plaster board, which is used to make walls in houses.

MICA has complicated crystal structure and a range of compositions, but, its main components are aluminum, iron, silicon, and oxygen. Mica breaks in flakes. Mica is fire proof. Ask students where they think mica could be used. Examples include toasters, old time stoves, or fire proofing.

CALCITE is made up of calcium, carbon, and oxygen. It is a very commonly used mineral in the cement business. The calcite the students have will make an image appear double when placed on top of it. This is because the way the molecules are arranged.

ULEXITE is made up of boron and oxygen. Ulexite crystals are fibrous (needle-like) in shape. This gives the mineral a special property; for complex optical reasons, images can travel along the fibrous crystals with little distortion. For this reason, ulexite is often called "TV rock," although it is a mineral. Ulexite is used to make some detergents, especially for washing clothes.

PYRITE is commonly called "fool's gold," because many inexperienced miners thought pyrite was gold. Pyrite is actually made of iron and sulfur. Pyrite crystals have cubic shapes, and a brassy color. Real gold is yellower than pyrite.

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