Mount Antero is where Colorado's state gemstone comes out of the rock

Colorado’s state gemstone has a specific home, and it is in Chaffee County, high on Mount Antero.

Aquamarine, the blue form of the mineral beryl, forms on the upper slopes of Mount Antero, near the top of one of the county’s fourteeners. The Colorado Geological Survey explains that the gems grow in pegmatites, coarse-grained pockets within the Mount Antero Granite. People have hunted these crystals there for well over a century, in thin air well above timberline.

Here is the part that surprises newcomers: finding aquamarine on Antero is not simply a matter of hiking up and digging. Much of the gem-bearing ground is held under private mining claims, which give the claimholder rights to the minerals. Collecting on a valid claim without permission is not allowed, and the terrain is high, steep, and exposed to fast weather.

For a new resident, this is a useful example of how mineral rights and public land overlap in Colorado. A peak can sit on national forest and still carry private claims that control what you can collect. The view is everyone’s; the crystals may not be.

For the geology and the claim picture, see the Colorado Geological Survey’s pages on gemstones and historic mining districts, and check land status before collecting anywhere on the mountain.