Transcript Minerals
Minerals Do Now 1. What is an atom? 2. What is a mineral? Provide 2 examples Objective SWBAT demonstrate understanding of how scientist develop a geological timeline through a quick quiz. SWBAT describe characteristics that all minerals share by answering the exit slip. Homework: Complete Mineral Worksheet #1 What is a Mineral? A mineral is a naturally occurring, inorganic, homogeneous solid with a definite chemical composition and an ordered atomic arrangement. Characteristics of All Minerals 1. Minerals are formed by a natural process. 2. Minerals are inorganic. 3. Every mineral is an element or a compound with a definite chemical composition. 4. Minerals are crystalline solids. What is a minerals structure? Minerals have a crystalline structure meaning that the atoms are arranged in a pattern that is repeated. A crystal is a solid in which the atoms are arranged in orderly repeat patterns. How are Crystals formed? Crystals are formed from either: Magma or a Salt Solutions Crystals from Magma Magma: hot melted rock material. Magma that cools fast produces small crystals. Magma that cools slow produces large crystals. Crystals from Solution 1. This happens when minerals dissolve in water. 2. When the water evaporates the ions left behind crystalize. OR 3. When there is more minerals than water the ions can crystalize. Mineral Composition and Groups Of the 1000’s of known minerals only a few dozen are common. 8 Elements form approximately 98% of the Earth’s crust. Minerals are classified according to the types of atoms in their structures and the way that the atoms are arranged. Mineral Composition and Groups The most common rock forming mineral is part of the group know as Silicates. Silicates are minerals that contain Oxygen and Silicon. (There is usually one additional element) Silicates make up most of the Earth’s crust and mantle. Common Rock Forming Minerals: Feldspar- Quartz (Silicates) Calcite (Carbonate) Exit Slip 1. List 4 characteristics of all minerals. 2. Describe how crystals of minerals are classified. Do Now What are the physical properties of minerals? List as many as you can Objective SWBAT: describe the physical properties used to identify minerals in an exit slip. Homework: Mineral Worksheet #2 Mineral Identification Color: Color may vary from one specimen of a mineral to another hence is not a very reliable property to help in mineral identification. Mineral Identification Hardness: The measure of how easy a mineral can be scratched. The Mohs Scale of hardness is used. This is a scale of 1-10. Talc is the softest:1 Diamond is the hardest:10 Mohs Scale of Hardness Mineral Identification Luster: The way a mineral reflects light. Can be metallic or non-metallic Metallic: Shine like metal Non-Metallic: Does not have a shine Mineral Identification Specific Gravity: The ratio of a minerals weight compared with the weight of an equal volume of water. Mineral Identification Streak: The color of a mineral when it is in a powdered form. This only works on minerals that are softer than a streak plate. Mineral Identification cleavage and fracture: Cleavage: The ability of a mineral to break apart in a consistent way. Break along smooth flat surfaces. Fracture: The inability of a mineral to break apart in a consistent manner. Break with uneven, rough, or jagged surfaces. Mineral Identification Other special characteristics: Magnetic- Magnetite Fizzes with HCL- Calcite Salty taste- Halite Smells like rotten eggs- Sulfur Exit Slip 1. Why is streaking more useful for mineral identification than color? 2. How is hardness used to identify minerals? 3. Give an example of a mineral that harder than a human fingernail and softer than Fluorite? (Reference page 69)