Types of gemstones: very hard version

There are so many problems with this quiz. It should be fixed or taken down. The sapphire pic is probably irradiated topaz, but not sapphire, the refractive index is too low. The malachite picture also contains marble, rose quartz and amethyst. The central stone in the jasper pic is turquoise or variscite, and there might not even be jasper in that pic, it's hard to tell. The topaz pic might have some topaz, but there's a lot of other stuff in that pic, including some synthetics based on the colors that don't occur in nature. The onyx appears to be primarily jet and lava based on the duller luster than onyx would have. This one is hard not because it's difficult, but because the clues are misleading, inconclusive, or downright innacurate.