1 / 16

2.3 – Physical Properties of Minerals

2.3 – Physical Properties of Minerals. Each mineral has specific properties that are the result of its chemical composition and crystalline structure. These properties provide useful clues for identifying minerals.

lillianw
Download Presentation

2.3 – Physical Properties of Minerals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2.3 – Physical Properties of Minerals Each mineral has specific properties that are the result of its chemical composition and crystalline structure. These properties provide useful clues for identifying minerals. Many of these properties can be identified by simply looking at a sample of the mineral or through simple tests.

  2. Color color: what color the surface appears property is easily observed but is VERY unreliable because minerals can be affected by impurities or weathering

  3. Streak streak: color of a mineral in powdered form more reliable than color for identification rub the mineral against an unglazed tile called a streak plate

  4. Luster luster: way a mineral reflects light metallic: reflects light like a polished metal

  5. nonmetallic: doesn’t reflect light like a metal glassy pearly earthy (dull)

  6. Cleavage & Fracture cleavage: mineral breaks along planes of weakness to form smooth, flat surfaces

  7. fracture: mineral breaks along irregular, rough surfaces (not flat!) conchoidal: breaks in a circular pattern (like chipped glass)

  8. Hardness hardness: ability of a mineral to resist scratching Mohs hardness scale: scale against which the hardness of minerals is rated • 1 = softest • 10 = hardest strength of the bonds that make up a mineral’s structure determines the hardness of that mineral

  9. to calculate hardness fingernail: 2.5 penny: 3.5 glass plate: 5.5 • try to scratch mineral with fingernail – if it can then the hardness is “less than 2.5”; if not, try with penny • if penny scratches mineral, hardness is “2.5 – 3.5”; if not, try the glass plate • try to scratch the glass with the mineral – if it can’t then the hardness is “3.5 – 5.5”; if it can then the hardness is “greater than 5.5”

  10. Crystal Shape crystal shape: general shape of mineral due to atoms always combining in the same pattern

  11. Density (Specific Gravity) density: ratio of mass to volume in a substance density = mass volume density remains the same regardless of size or shape of mineral if you cut a mineral in half, you would have half the mass and half the volume so the same density (ratio!)

  12. Special Properties of Minerals Fluorescence & Phosphorescence fluorescence: ability to glow under ultraviolet light phosphorescence: ability to glow after the ultraviolet light is turned off

  13. Chatoyancy and Asterism chatoyancy (cat’s-eye effect):mineral displays a silky appearance in reflected light asterism: a six-sided star appears when a mineral reflects light

  14. Double Refraction double refraction: produce a double image of any object viewed through the mineral

  15. Magnetism magnetism: minerals attracted to magnets • these minerals may be magnetic themselves nonsilicate minerals that containironare more likely to be magnetic than silicate minerals Radioactivity radioactivity: unstable atoms (isotopes!) decay by releasing particles & energy to form stable atoms

More Related