Chalcedony

Chalcedony- By Adam Carey and Ross Enderson

**//__ Chalcedony __//**

What is chalcedony made of? Varieties of cryptocrystalline quartz gemstones What is its hardness? Seven What colors is it made of? Orange, yellow, green, sky blue, blue, purple, pink, white, black, and sometimes multicolored What is its luster? Waxy to glassy What is its streak? White What is its density? 2.6 g/cm cubed What is its crystal structure? Trigonal Cleavage/Fracture- No cleavage, uneven fracture Special Characteristics- This is used in gemstones, worn by the Romans to promote calmness and peacefulness. Where is it found? Mexico, Madagascar, U.S., India, Burma, and Brazil How does it form? Forms over long periods of time as minerals are deposited into the pocket in another form of rock such as granite. Made mostly around volcanic areas. Uses for chalcedony: Good decorative stone; carved into cabochons; make fine gems Is it found in Iowa? No

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