A mineral is a naturally occurring inorganic solid with a specific chemical composition and a crystalline structure. Minerals are the building blocks of rocks, and they have various physical properties that can be used for identification.
Properties of Minerals
Minerals have several distinguishing physical properties:
Color: The color of a mineral can vary, but it is not always a reliable indicator for identification.
Luster: This refers to the way lightreflects off the surface of a mineral. Common types of luster include metallic, glassy, and dull.
Hardness: The Mohs scale is used to measure the hardness of minerals, ranging from 1 (softest, like talc) to 10 (hardest, like diamond).
Streak: The color of the powdered form of a mineral, which can differ from the color of the mineral itself.
Cleavage and Fracture: Cleavage is the way a mineral breaks along flat surfaces, while fracture refers to irregular or uneven breaks.
Crystal Habit: The natural shape in which a mineral tends to grow.
There are thousands of identified minerals, but some of the most common ones include:
Quartz: A hard mineral often found in igneous and metamorphic rocks.
Feldspar: A group of minerals that are the most abundant in the Earth'scrust.
Mica: Known for its perfect cleavage and ability to split into thin, transparent sheets.
Calcite: A major component of limestone and marble, with a characteristic rhombohedral cleavage.
Halite: Commonly known as rocksalt, often forming in evaporite deposits.
Study Guide
Here are some key points to remember when studying minerals:
Understand the definition of a mineral and its essential characteristics.
Learn to identify minerals based on their physical properties, such as color, luster, hardness, and cleavage.
Be familiar with the processes of mineral formation, including crystallization from magma, precipitation, and metamorphism.
Memorize the properties and common examples of important minerals like quartz, feldspar, mica, calcite, and halite.
Remember to practice identifying minerals using their physical properties and study the specific characteristics of common minerals to deepen your understanding of this topic.
The student demonstrates an understanding of how science explains changes in life forms over time, including genetics, heredity, the process of natural selection and biological evolution by showing the relationship between physical characteristics of Alaskan organisms and the environment in which they live.