Rocks and Minerals

These minerals may be grouped together because they all have —

• the same crystal systems

• constant density values

• shiny streaks

• the oxygen ion

Granite forms when magma cools and hardens below the Earth’s surface. It is classified as—

• an igneous extrusive rock

• an igneous intrusive rock

• a sedimentary rock

• a metamorphic rock

The diagram shows a test for which mineral property?

• Hardness

• Luster

• Cleavage

• Streak

All of the following are characteristics of metamorphic rocks except —

• flattened crystals

• parallel layers

• bending from pressure

• holes from trapped gases

Igneous rocks are formed by—

• heat and pressure on existing rocks

• evaporation of water, leaving solids behind

• cooling and hardening of molten rock

• compaction of layers of mud on the bottom of a lake

Which of the following minerals found in Virginia is known as “fool’s gold”?

• pyrite

• hematite

• galena

• limonite

Which conclusion can be made based on the information in the chart?

• Quartz is harder than topaz.

• Calcite is harder than apatite

• Fluorite is harder than feldspar.

• Gypsum is harder than talc.

More often than metamorphic or igneous rocks, sedimentary rocks have —

• many holes from trapped gases

• large quartz crystals

• numerous fossils

• a glassy appearance

Tags

NGSS.MS-LS4-1

Which of these can determine the size of grains in igneous rocks?

• amount of rare minerals

• distance from a plate boundary

• size of the volcano

• cooling rate of molten rock

What property is shared by many gemstones, such as diamonds, rubies, sapphires, emeralds, and topaz?

• extreme hardness

• high specific gravity

• carbon as the primary element

• ductility