Botryoidal chalcedony!

Plume agate is a variety of chalcedony, a microcrystalline quartz, characterized by delicate, plume-like inclusions of various colors and minerals. These inclusions often resemble feathers, flowers, or flames, giving the agate a unique and visually appealing appearance.

Plume agate only forms in hotsprings with the help of thermophiles and extremophiles (microscopic organisms that like harsh and hot environments) collecting silica and other dissolved particles in silica rich hotsprings and depositing them in wild patterns within the agate.

A combination of clays, metals and minerals make up the cool colors and textures we experience.

There are many famous deposits of plume, flame and other varieties of textures made with the assistance of microbes.