The field test for a diamond is hardness. You can scratch another rock or a test piece of glass with the edge of the stone. Note, however, that the field test is not conclusive.
Your price for any diamond depends on the cut, carat weight, colour and clarity of the diamond that you want to buy.
Any diamond, at any time, is valued by its carat weight, its colour, its clarity and its cut.
I don't think rocks can be any colour because a group of the same type of rock contain the same minerals which would make all that type of rock the same colour
Sandstone (any colour) is a sedimentary rock.
A peridot is a peridot; a diamond is a diamond. They are different gemstones. If 'peridot' is used as a word to modify the description of a diamond, one might deduce that the diamond had a slight lime-green colour. Any diamond's value is based not only on its colour, but its cut, carat weight and clarity.
A diamond is valued by its cut, clarity, carat weight and colour. Depending on your taste, you can buy a diamond in most any colour; and pay most any price for the stone you want. "Good" is relative. The highest colour grade for a 'colourless' diamond is D. Otherwise, in a coloured stone, the highest colour grade is Vivid Fancy [colour].
When a diamond is crushed into dust, it appears colorless. This is because diamonds are typically transparent and colorless in their natural state. The crushed diamond dust may appear sparkly due to its structure, but it does not display any specific color.
Every diamond is valued by its cut, clarity, colour and carat weight, even American diamonds.
Yes, the mineral we know as diamond is harder than any steel. Diamond is the hardest substance we know of.
No, chocolate diamonds are not man-made. They are a natural variety of diamond that get their distinct brown color from the presence of nitrogen during their formation process. They are also known as champagne or cognac diamonds.
Crystal is a broad term that usually means any kind of shiny rock/mineral that can be used as jewelry. Diamond is just a type of "Crystal", so your question can't really be answered.
Any diamond mine can practically deliver any colour of diamond. However, Australian diamond mines are currently building and enhancing their reputation for pink diamonds. You can read more, below.