Harvesting amethyst shards from amethyst crystals is pretty easy if you can track the crystals down. That said, these crystals are pretty elusive, even on Minecraft’s terms. Amethyst crystals can only generate inside of a new small cave generation type called the Amethyst Geode.
The geode is made up of geode blocks, which are a block type that isn’t able to be obtained with any tool currently in the game, not even with the silk touch enchantment. You can recognize a geode block by its unique purple color and shiny looking design, even if you can’t see any crystals yet and even though it does not emit light.
You can only find amethyst geodes underground, as it is a type of cave generation. That said, it is extremely tiny, and since there is no tell in the overworld as to where it’s located like with the Lush Caves and their acacia trees, tracking one down may seem near impossible.
That said, there is a way to know one is nearby, even if you don’t yet have any visual signs. When you are in or near an amethyst geode, you will hear the sound of bells chiming. It is not clear whether these radiate from the blocks, the crystals, or from the location itself similar to the way the mineshaft had minecart sounds.
Once you have located the geode, you can harvest amethyst shards which can be used to create the brand-new telescope tool. Whether or not the shards will also have other uses remains to be seen.