2What is a Mineral?A mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition.
3A. 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
4B. 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
5C. SolidSolids are substances that have a definite shape and a definite volume.The particles are tightly packed and can not flow freely.
6D. 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
7E. 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.
8Identifying Minerals Each mineral has its own characteristics or propertiesthat help you identify it.
9Identifying 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.
10Identifying 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
11Identifying 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.
12Identifying 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.
14Identifying Minerals E. Density The density of a mineral always remains the same.Density measures the “heaviness” of an object.
15Identifying 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