stone or metal.... stones are much less rare than other things. Diamonds are rare, for example compared to silicon/iron/nickle/carbon rocks and stones (earth), but not rare when you compare it to say, gold (which all gold worldwide would only make a cube 25 meters per side (worth about 2500 trillion), platinum a cube only about 6.3 meters per side.
For rare gems, theres Andesine and Labradorite (discovered in 2002) go for 1500-2000 per carat raw (basically only found in one place so far).
Unfortunately it\'s hard to get facts about \'rarity\' of stones because all the "precious stones and metals" have the market demand and artificially inflated prices (and thousands of websites) mixed in.
