Minecraft wiki entry for Things_not_to_do, associated text: Budding amethyst is unobtainable in Survival and is the only source of amethyst buds, clusters, and shards. This block can be hard to make out in an amethyst geode among all the normal amethyst blocks, but it has an X-shaped crack on each face and is often seen growing amethyst buds or clusters. To farm amethyst, it is advisable to mine out all the blocks touching each face of a budding amethyst block (unless it is another budding block) and allow each face to grow shards. As this can only be done in the geode in which the budding blocks are found, noting down the coordinates or building a distinct landmark would be a good idea.