Prospectors have long had the task of telling the difference between gold and "fool's gold." If you were in the field, and given samples of gold, pyrite and chalcopyrite, how would you distinguish them from one other? Be sure to note properties you could use to accurately identify all three.

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Foster

Geography

5 August, 11:37

Prospectors have long had the task of telling the difference between gold and "fool's gold." If you were in the field, and given samples of gold, pyrite and chalcopyrite, how would you distinguish them from one other? Be sure to note properties you could use to accurately identify all three.

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Emmett Haynes · Answer 1

1. Magnetic Properties

Gold in its pure form is not magnetic. If it is placed in a magnetic field, it will magnetize a bit only as long as it is still in the field.

Pyrite on the other hand would stick to a magnet because of its high iron content; same with chalcopyrite.

2. Physical Properties

Gold is highly malleable and ductile. While pyrite and chalcopyrite are both brittle, however, pyrite is harder than chalcopyrite. However, a sample of chalcopyrite would be easily scratched with a nail while pyrite won't.

3. Color

Although, the three might possess almost the same color confusing prospectors, a simple shade test will set them apart. Gold will remain the same even in bright sunlight and in a shade however, pyrite and chalcopyrite change color when viewed in shade. Pyrite and chalcopyrite will look brassy dull yellow or dark in shade.

4. Weight

When flaky and spread on a pan of water, gold sinks to the bottom while pyrite and chalcopyrite floats.

5. Chemical Test

Using Nitric acid, place a few drops on each samples, pyrite and chalcopyrite would definately change color usually to black while gold remains the same.