Chapter 1 - the Rock Cycle Flashcards
What are minerals?
a naturally occurring, nonliving solid that has a specific chemical makeup and a crystalline, or repeating structure
How are minerals identified?
using mineral properties
What are some characteristics of mineral properties?
color, streak, luster, and hardness
COLOR alone cannot be used to identify a mineral. Scientists need to use additional properties when classifying most minerals. STREAK is the color of the powder left behind when you rub a mineral against a streak plate. Many minerals make a streak the same color as the mineral, however, some do not. Streak is a better property for mineral identification than color. LUSTER is the way a mineral’s surface reflects light. Many minerals have a METALLIC luster, others have a NONMETALLIC luster. A nonmetallic mineral can be described as dull, glassy, pearly, waxy… Some minerals are HARD and can’t be scratched and others scratch easily.
What is the Moh’s Scale and what is it used for?
created by German scientists and ranks minerals from 1 to 10 according to their hardness. Talc is the softest mineral and diamond is the hardest mineral (talc = 1, diamond = 10). Any mineral higher on the scale can scratch any mineral lower on the scale.
What is a rock?
a natural solid made of one or more minerals. Most rocks are mineral mixtures.
What are 3 types of rock classifications? And how are classified?
Igneous, Sedimentary, and metamorphic
Depending on HOW they are formed they can be classified
What is an igneous rock?
a rock that forms when MELTED ROCK COOLS and HARDENS. Igneous rocks can form underground or on Earth’s surface. Igneous rocks that form underground cool much more slowly than those on the surface because below ground has more heat. When melted rock cools slowly, mineral crystals have time to grow. So igneous rocks that form UNDERGROUND HAVE LARGE CRYSTALS. When melted rock cools quickly (above ground) minerals don’t have time to grow large. So they have small or no crystals.
name some types of igneous rocks
basalt, gabbro, pumice, obsidian, rhyolite, granite
What is sedimentary rock?
a rock that forms at relatively LOW TEMPERATURE as bits of minerals and rocks become squeezed (cemented - compressed) and stuck together.
example: heat of the sun causes cracks in rocks; in the winter, rain and snow enter the cracks and freeze. The ice expands, breaking off more pieces of the rock. The rock is slowly being worn away.
SEDIMENTS, or little pieces of rock, are carried off by water and wind. It is DEPOSITED, or set down, in various places.
What is DEPOSITION?
When sediment is dropped by wind and water. It is carried away and then dropped in a new place.
name some types of sedimentary rocks
conglomerate, sandstone, shale, limestone
What is a metamorphic rock?
Rocks that change form. Meta = change, morphic = form. When a rock is changed by heat and pressure, the new rock is called metamorphic. They can form from any other rock including igneous, sedimentary, and other metamorphic rocks. Metamorphic rocks can be found in mountain ranges, underneath many layers of other rock, or near volcanoes.
name some types of metamorphic rocks
schist, gneiss, slate, quartzite, marble
What can rocks be used for?
tools, surgical instruments, to build buildings, to make building materials
What is weathering?
the process of wearing away rocks by natural processes (wind, water, ice, sunlight). All these factors break down rocks into sediments. Weathering is the beginning of a process that changes rocks on Earth’s surface.
