A: I’d be willing to bet that the desired stone is what we in the English language call Chrysocolla. In it’s best form, it is a somewhat rare and pricy type of chalcedony (like agate, only usually not banded) which is translucent and colored light to medium blue from inclusions of a copper carbonate mineral. Pure chrysocolla itself is very soft, similar to turquoise or malachite, only usually more so. Usually it’ has an impure mix of various copper minerals along with it, including malachite, variscite, cuprite, azurite and others. In Israel they call it Eliat stone. In Mexico and Arizona, a material called “parrot’s wing” is often seen which is essentially chrysocolla. There are other variations as well, which are all usually quite inexpensive.