Amethyst Geode
Amethyst Geode is a naturally generated underground structure found throughout the Overworld, recognizable by its distinctive layered, spherical form. It can appear in virtually any biome between Y=-58 and Y=30, with each chunk having roughly a 1-in-24 chance of attempting to produce one. When a Amethyst Geode forms, it displaces the surrounding terrain — including caves, aquifers, and canyons — to carve out its characteristic shape.
The structure is built from three concentric shells. The outermost layer is composed of smooth basalt, followed by a middle ring of calcite, and finally a hollow interior lined predominantly with blocks of amethyst. Scattered among those amethyst blocks, around 8.3% are replaced by budding amethyst, which are the only blocks capable of growing amethyst crystals. These crystals appear in four stages — small buds, medium buds, large buds, and full clusters — and can be found dotting the inner walls of the cavity.
Roughly 95% of all Amethyst Geode structures generate with at least one crack in their outer shell, exposing the interior without requiring players to mine through the basalt layer. This makes the amethyst crystals inside relatively easy to spot and harvest. The Amethyst Geode serves as the primary natural source of amethyst shards and blocks of amethyst in the game, both of which have uses in crafting items such as spyglasses and tinted glass.
The Amethyst Geode was introduced alongside the Caves & Cliffs update, first appearing in Java Edition snapshot 20w45a and releasing fully in Java Edition 1.17. In Java Edition it is identified as the configured feature 'amethyst_geode', while Bedrock Edition refers to it as 'amethyst_geode_feature'.