4To Be a Mineral a Substance All Five Characteristics Must HaveAll Five CharacteristicsNow I See Crystal Clear!Naturally OccurringInorganic (Was Never Alive)SolidCrystal StructureChemical Composition
5Must be formed by processes in the natural world. Naturally OccurringMust be formed by processes in the natural world.Mineral Quartz forms naturally as molten material cools and hardens deep beneath Earth’s surface.
6NO Are man made materials like Plastic, brick, glass, and steel can be called minerals?NO
7A mineral can not form from organic materials (living things). Mineral has to be InorganicRemember:A mineral can not form from organic materials (living things).Is coal a mineral?No, it comes from the remains of plants that lived millions of years ago.
8Has definite volume and shape Mineral is always a solidHas definite volume and shapeMineral has a crystal structureA solid in which the atoms are arranged in a pattern that repeats again and again.Has flat sides, called faces, that meets at sharp edges and corners.Like a snowflake pattern or rock candy.
9Always contains certain element in definite proportions. Mineral has a Definite CompositionAlways contains certain element in definite proportions.Quartz has one atom of silicon for every two atoms of oxygen.
10Rarely is a mineral identified by a single property. Identifying MineralsRemember!:Rarely is a mineral identified by a single property.These properties need to be considered together to correctly identify a mineral.
11Of the almost 4000 known minerals, only about 30 are common. The most common are:quartz, feldspar, mica, and calcite.
12Fact:Over 60% of the Earth’s crust is made up of the family of minerals known as feldspar!
14There are four common minerals, how many can you name? Discuss the following!There are four common minerals, how many can you name?Of the four common minerals, which one makes up over 60% of the Earth’s crust?
15To be able to identify these and other minerals, we need to look at the properties used to separate and distinguish these minerals.
16ColorColor is the most easily observed mineral property and the least useful!Mineral azurite is always blue.Mineral malachite is always green.
21How many of the characteristics of minerals can you name? Discuss the following!How many of the characteristics of minerals can you name?Why isn’t color a very good property to identify most minerals?
22StreakStreak of a mineral is the color of its powder when rubbed on an unglazed white (porcelain) tile.
23The streak is often not the same color as the mineral. A mineral’s color may vary, but the streak rarely will!Mineral sulfur has yellow color,but produces streak of white color on black tile.
24StreakFor example, Calcite occurs in many different colors, shapes, and varieties. But every single variety of Calcite has a white streak. A streak is useful in distinguishing two minerals with the same color but different streak.
25StreakMinerals, which streak very light colors, can be easily identified on black streak plate.
26Notice the difference between these two minerals? LusterThe way a mineral reflects light from its surface.Notice the difference between these two minerals?
27LusterThe mineral on the left has a metallic luster, the one on the right, a nonmetallic luster.GalenaQuartz
45Does this mineral show cleavage or fracture? Discuss the following!Does this mineral show cleavage or fracture?Of the four most common minerals,which has the highest hardness?Which has the lowest hardness?
46Most mineral grains that are found in rocks, lack the room to grow. Crystal ShapesCrystal shape can be a useful property to identify minerals if the minerals have had the time and space to form crystals.Most mineral grains that are found in rocks, lack the room to grow.
47Pure gold can have a specific gravity as high as 19.3! Specific gravity tells you how many times as dense as water the mineral is.Pure gold can have a specific gravity as high as 19.3!
48Calcite is calcium carbonate, CaCO3. Acid TestCalcite is calcium carbonate, CaCO3.If a drop of weak hydrochloric acid is placed on calcite, the acid bubbles as carbon dioxide is released.
49Other Special Properties Magnetic Malleable Radioactive Flourescence Taste
50Can you think of a mineral that might be shaped or hammered? Malleableor DuctileMinerals that can be hammered thin or shaped are said to show these properties.Can you think of a mineral that might be shaped or hammered?