Yes.
Diamond
Yes.
Yes, there are a few minerals that are stronger than diamond. Wurtzite boron nitride and lonsdaleite are both harder than diamond on the Mohs scale of mineral hardness. However, these minerals are very rare and not commonly found in nature.
The blue variety of a rare mineral used as a gemstone is called blue diamond. Blue diamonds are highly sought after for their rarity and unique color.
All diamonds are minerals, and most all diamonds are rocks in their raw form: exceptionally hard, clear rocks.
Well the mineral Tanzanite, a the blue/purple variety of the mineral zoisite, discovered in the Meralani (Merelani) Hills of Northern Tanzania in 1967, is very beautiful and as it is ONLY found in this one place (and the deposit is running out), it could be regarded as the most rare gemstone mineral.However, you could argue that the blue 'Hope' diamond or a large pink diamond is the rarest and most beautiful mineral.
Diamond is the hardest mineral and can only be scratched by another diamond.
The mineral that can only be scratched by diamond is diamond itself. Diamond is the hardest known natural mineral, scoring 10 on the Mohs scale of mineral hardness.
Mineral X could be anything. Diamond is the hardest mineral (10 on Mohs' scale) and can scratch all other minerals including another diamond.
A diamond. Actually, a diamond can be scratched my other minerals.
quarts
Yes a diamond is a mineral. It is the hardest mineral on the Moh's Hardness Scale from the ratings 1-10.