Sorry but I’m don’t know these things
Answer:
The hardness rating is 4.
Explanation:
Calcite sits at a hardness rating of 3 and is very easily scratched with a knife and/copper coin. This is where most Marbles, limestones, travertines, rate.
Meanwhile, Fluorite sits at hardness 4 and can be scratched by a knife.
Positron Emission Tomography scan of the brain of cocaine addicts showed that the drug affects how the brain use glucose. Cocaine users' brain cannot use glucose efficiently and there are also reduced metabolic activity in other areas of the brain.
Somewhat met in the nature
