1. #23 Specific Gravity Lab #2 Winter 2007 Note : Linda …this assignment is a “back up assignment ---and is essentially an extension of the first Specific Gravity Lab. I want you to assign this if you feel the great majority of students are done with the 3 other labs ---- and if some “filler” is needed. Formula for Specific Gravity : mass of sample in air / loss of weight in water

2. Specific Gravity Lab I. TITLE II. PURPOSE : to identify the specific gravity of minerals and determine which of the mineral groups (silicates, carbonates,oxides, sulfates and sulfides, halides ) has the highest specific gravity. III. PROCEDURE : use the process for determining Specific gravity for the minerals indicated

3. Place mineral in water and weigh Allow mineral to hang in air from spring scale and determine mass in grams

4. Make a loop of string to suspend mineral from hook on spring scale Prepare a slip knot to hold one end of string on scale …and the other end on the mineral. Experiment to find the a knot that will hold.

5. Specific Gravity Formula Specific Gravity Use these formulae: Density = mass / volume Volume = mass / density

6. MineralMass On scale (g) Volume (cm3) determined by displacement Density mass/ volume (g/cm3) Weight in air (g) Weight in H20 (g) Specific gravity (dimension -less) Halite Quartz Iron Pyrite Hornblende Augite sphalerite Hematite Cassiterite

7. Mineral Mineral group s– name the group that the mineral belongs to ) (silicate, carbonate, oxide, sulfate and sulfide, halides, or native elements) Halite Quartz Iron Pyrite Hornblend e Augite sphalerite Hematite Cassiterite

8. Specific Gravity Graphs: Label all graphs…and all graphs must be full page Specific Gravity Minerals Density g/cm3