2 What is a Mineral?A mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition.
3 A. Naturally occurringA mineral has to be found on the earth's surface or dug up out of the crust, not made in a lab somewhere by people.Examples of man-made objects arebricks, cement,and glass
4 B. Inorganic This means that they do not come from living things. Since coal forms naturally in the crustand from living things it is not a mineral
5 C. SolidSolids are substances that have a definite shape and a definite volume.The particles are tightly packed and can not flow freely.
6 D. Crystal structureThe atoms that minerals are made of are connected to each other in a pattern. This pattern is called its crystal structure.The flat sides form faces
7 E. Definite Chemical Composition This means that there is a specific chemical formula for each mineral. The mineral pyrite is made of 1 atom of iron for every 2 atoms of sulfur. (FeS2)Pyrite will have the same chemical formula regardless of where it is found.
8 Identifying Minerals Each mineral has its own characteristics or propertiesthat help you identify it.
9 Identifying Minerals a. Hardness Hardness is one of the best clues to identify a mineral.Mohs hardness scale ranks ten minerals from softest to hardest.A mineral will scratch any mineral softer than itself.
10 Identifying Minerals B. Color Color is a physical property that is easily observed, however not many minerals have distinct colors.Malachite is always greenAzurite is always bluemalachite
11 Identifying Minerals C. STREAK Streak refers to the color of a mineral’s powder.Testing a mineral’s streak is done on an unglazed piece of tile.Although a mineral’s color may change its streak color does not.
12 Identifying Minerals D. Luster Luster is another simple test for determining a mineral.Luster refers to how a mineral reflects light.Metals are often shiny other minerals may be glassy,waxy or pearly.Tourmanline has a vitreous (glassy) luster.
14 Identifying Minerals E. Density The density of a mineral always remains the same.Density measures the “heaviness” of an object.
15 Identifying Minerals G. how it breaks The way a mineral breaks apart also can help identify it.If it splits easily along flat surfaces it has a property called cleavage.However if it does not break evenly it has a characteristic type of fracture.Calcite hascleavageCopper willfracture