Oscilica

Oscilica generates in the outer End islands as a renewable alternative to sand. The block behaves much like sand, but it does not fall, it is mined with a shovel, and it drops Dead Oscilica unless broken with Silk Touch. Dead Oscilica can be revived with a Ghast tear, and smelting it produces glass, unlike regular sand. A cactus can grow on Oscilica, and Oscilica is also generated inside End Quartz Ore, where it is never exposed to air because Endermen pick up the block.

The Oscilica Pileus is the structure that grows from an Oscilica block when it is fed Quartz items or Quartz blocks through dispensers, up to five at a time. Each feeding adds a growth and generates new structure around it. A full Pileus measures 65 by 65 blocks horizontally and 26 blocks tall, and building one takes 7082 blocks, about 110 full stacks plus 41 Quartz items. Oscilyst, a solid block that grows at the edges of the Pileus with a 1 in 1024 chance, gives four Oscilyst Slices, and an Oscilyst Slice can be crafted with 12 Sugar.

Oscilica runs on the client and the server, so the server and every player need the mod, and it requires Fabric API. It is published for Fabric only, for 1.21.8, 1.21.9 and 1.21.10, with 1.0.1 for 1.21.10 as the latest file. The code is under the MIT License and is not open source.