The material met all the criteria required to be called a mineral. • The substance was said to be inorganic. The item was actually proven to be an element on the Periodic Table. Water which is indicated by the symbol H2O is considered a compound. Sodium chloride (NaCl) has a crystal structure. Opal has a luster that is considered greasy. Green fluorite has prominent cleavage. When native copper is torn, it results in what is referred to as hackly fracture. One can tell that pyrite is not gold, because it leaves a black streak. Galena is Lead ore. According to Mohs hardness scale, diamond is the hardest solid to be tested. Now it’s your turn, you will have 3 minutes to discuss this will your group, starting NOW. Mineral: A naturally occurring, inorganic, solid that has a crystal structure, and a definite Chemical composition. Inorganic: Not formed from living things or remains of living things. Element: A substance composed of a single kind of atom. Compound: A substance in which two or more elements are chemically joined. Crystal: A solid in which the atoms are arranged in a pattern that repeats again and again. Luster: The way a mineral reflects light from its surface. Cleavage: A mineral’s ability to split along a flat surface. Fracture: The way a mineral looks when it breaks apart in an irregular way. Mohs Hardness Scale: A scale ranking ten minerals from softest to hardest; used in testing the hardness of minerals. Ore: Rock that contain a metal or economically useful mineral. Streak: The color of a mineral’s powder.