Answer:
Galena
Explanation:
Galena usually occurs in cubic crystals. If you hit a specimen of galena with a hammer it will shatter into small perfect cubic crystals. It has a metallic luster and a black to dark gray color and streak. Galena has a hardness of about 2.5 on the Mohs hardness scale which is about as hard as your fingernail.
Answer:
Explanation:
Statistics show around 25% are able to relapse after only 1 year.