Unformatted text preview: will scratch glass. Cannot be scratched with a knife blade or masonry nail. Soft Minerals – will not scratch glass. Can be scratched with a knife blade or masonry nail. Cleavage – the tendency of some minerals to break along flat, parallel surfaces like the flat surfaces on broken pieces of galena. Fracture – any break in a mineral that does not occur along a cleavage plane. Tenacity – the manner in which a substance resists breakage. Reaction To Acid – test minerals with acid to see if it fizzes. Striations – straight “hairline” grooves on the cleavage surfaces of some minerals. Magnetism – influence minerals, tested with magnet. Specific Gravity (SG) – the ratio of the density of a substance divided by the density of water....
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- Spring '08
- Mineralogy, Crystal, Luster, characteristic chemical composition