The usage of 'in' out of this sentence "The wealth of Moria was not in gold or jewels but mithril." I came across a sentence in LOTR film : "The wealth of Moria was not in gold or jewels but mithril." I am a little confused by the usage of "IN" there. I suppose that it probably can be paraphrased like this: The wealth of Moria was not gathered by mining for gold or jewels but mithril. Am I right? Can you please tell me if I properly made the following sentence using 'in' the same way as the one above. And I wonder if it sounds poetic and natural as well. [1] "The wealth of the Middle East has been in oil." [2] "The wealth of him must be in drug." Thanks in advance.