Field Notes from Artigas · 01
Columns inside the rock
When some geodes from Los Catalanes are opened, something unexpected appears inside the stone: vertical columns, like a cave in miniature.
First an agate core forms, sometimes hollow. Then colorless quartz coats it, and amethyst grows on the quartz. Cut across, the column shows that history in rings: agate at the center, amethyst on the outside.
They are one of the things we look at most closely when a piece appears.