Grey Agate slice with banded pattern

This is a natural agate slice, a type of chalcedony quartz that forms in volcanic rocks. Agates develop their distinctive banded patterns over millions of years as silica-rich solutions fill cavities in rock, depositing layers of mineral that create concentric rings or bands.

This specimen would appeal to mineral collectors, crystal enthusiasts, and home decor aficionados who appreciate natural geological formations. 

The translucent quality and banded pattern make it desirable for display purposes, either as a standalone decorative piece or incorporated into jewelry or functional items like bookends or paperweights.

Brazil

Geological formation millions of years old; cut in recent decades