GEOL 1250 Lecture Notes - Lecture 4: Crystallin, Talc, Atomic Number

• School: University of Georgia
• Department: Geology
• Course: GEOL 1250
• Professor: Patino- Douce

Document Summary

Rocks are made up of minerals which are made of atoms of chemical elements. Specific chemical composition (not fixed - they are within a defined range) Naturally formed solid that is part of a planet. Rocks are not minerals but (many) are made up of minerals: they are mineral assemblages (group of minerals) Constant angles between rows and planes of atoms. Color - sometimes from impurities in formation. Cleavage - weak points/ directions where crystal breaks easily. Attractions and repulsions between ions balance out to give a stable (lowest energy) structure. Atomic number (number of protons) defines identity of atoms. Atomic mass (number of protons and neutrons) can vary among atoms of the same element. Minerals are chemical compounds - electrically neutral combination of atoms. Minerals with ionic bonds tend to be soluble in water. Minerals with covalent bonds tend to be insoluble in water. Electrons are free and form a cloud around the cation.