No, there is no correlation between color and hardness in minerals.
false a mineral can not scratch any mineral harder than itself
false. if a mineral is harder than another mineral, it would be able to scratch the softer one
diamond
Yes. Diamond.
The mineral fluorite is harder than calcite. Fluorite is represented as a 4 on the Mohs scale of relative mineral hardness, calcite is a 3.
calcite
If you mean isn't harder than quartz but harder than apatite ( you spelled it wrong), that would be Orthoclase Feldspar. Else the minerals that are harder than both apatite and quartz are topaz, corundum, and diamond (diamond being the hardest, well the hardest non synthetic mineral).
Yes, diamond is harder than granite. Diamond is the hardest mineral known. And it is several times harder than granite.
Our crystal ball has been broken, so we are not able to predict what might happen in the world should a mineral harder than diamond be discovered in future.
No, diamond is the hardest known mineral.
Magnetite
No, diamond is the hardest naturally occurring mineral.