GEOL 1121L Lab 3 (2026/2027) (PDF) | Minerals Lab | Intro to Geology | GSU

INSTANT PDF DOWNLOAD This GEOL 1121L Lab 3 Guide supports students in Introduction to Geology at Georgia State University (GSU). Lab 3 focuses on mineral identification, physical properties, and how minerals form — foundational skills for all geology labs. Students learn to identify minerals using observable characteristics and standard testing procedures used in geoscience. 1. What is a Mineral? A mineral must be: Naturally occurring Inorganic Solid Definite chemical composition Ordered internal crystal structure 2. Physical Properties Used for Identification Color Visible surface color Often unreliable due to impurities Streak Color of powdered mineral More diagnostic than surface color Luster Metallic vs. nonmetallic Vitreous, pearly, dull, silky, etc. Hardness Mohs Hardness Scale (1–10) Scratch testing method 3. Crystal Form & Structure Crystal faces and geometry Atomic arrangement controls external shape Silicate tetrahedron (SiO₄) basic building block