This document provides information about minerals, including their formation, composition, properties, and crystal structures. It discusses how minerals are the building blocks of rocks and are made up of arrangements of atoms. There are over 2,500 known mineral types that are classified based on their chemical composition and crystalline structure. Common properties described for identifying minerals include color, streak, luster, hardness, cleavage, and crystal shape.

1. Chapter 5 Minerals

6. Silicate Minerals Amphibole group Feldspars Micas Quartz

7. Non-Silicate Minerals Halite (NaCl) Calcite (CaCO3) Halite (NaCl) Gypsum (CaSO4 (+2H2O)) Hematite (Fe2O3)

8. Non-Silicate Minerals Pyrite (FeS2) Sulfur (S)

13. Shapes of Mineral Crystals Tetragonal crystals are shaped like cubic crystals but are longer in one direction making shapes like double pyramids and prisms. Cubic crystals are not always cube shaped! There are many that are shaped like octahedrons (eight faces), and some that are shaped like dodecahedrons (10 faces).

14. Triclinic crystals are sometimes very strange shapes! They are usually not symmetrical from one side to the other. Orthorhombic crystals are often shaped like rhombic prisms or dipyramids (two pyramids stuck together). They often look a bit like tetragonal crystals except that they are not square in cross section (when you look at the crystal on end).

15. Monoclinic crystals look like tetragonal crystals that have been skewed. They often form prism shapes and double pyramids. Hexagonal crystals often look like six-sided prisms. When you look at the crystal on end, it looks like a hexagon shape in cross section.