About 20% of all diamonds mined can be cut and polished into gemstones -- and in that case, you could call one a 'polished rock'.
'Polished rock' is not considered a natural state for a raw diamond, however.
Diamond. Diamond is, for example, polished with diamond powder.
It isn't inside of the polished stone.
A polished diamond is an example of complete diaphany, in that you can see through it.
The diamond cutter taught the intern how a diamond cuts diamond as they cut and polished the raw stone.
They are ground on "Diamond wheels" and laped with "Diamond dust" then polished.
slickenslides
Yes.
Yes, any rock that is pitted grooved or polished is usually caused by wind abrasion.
Yes, a raw diamond will always test as a diamond.
When raw diamonds are cut and polished, a 'diamond dust' is released. It is collected and re-employed in the diamond polishing process.
Diamond Rock happened in 1805.
Diamond is a stone, a rock, a geological phenomenon. Once mined, polished and sold, it can be mounted in jewelery (while 75% of all mined diamonds are used industrially). When describing an object for sale, for example, one might say that -- of the gemstone mounted in the jewelery -- the 'stone type' is diamond.