Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Owyhee Blue Agate

A soft sky-blue chalcedony from the Owyhee region of Oregon and Idaho, prized for its calming, opaque powder-blue color.

A soft sky-blue banded chalcedony prized for its delicate, lace-like white and blue swirling patterns.

A rare translucent lavender-blue agate from the Holley area of Oregon, prized for its soft purple-blue color.

A chalcedony agate marked by round, concentric ring patterns that resemble eyes when cut and polished.

A translucent, soft blue variety of microcrystalline quartz whose color comes from light scattering through its fine structure.

Glacially deposited banded agates found along Lake Michigan beaches, small waterworn pebbles with concentric red and grey banding.

A banded fortification agate from the remote Dryhead area of south-central Montana, prized for warm concentric rings.

A swirling, intricately banded lace agate from Eswatini (Swaziland) in soft greys, blues and lavenders with delicate folded patterns.

A waxy, translucent microcrystalline form of quartz that serves as the parent group for agate, jasper, carnelian, and onyx.

A rare, intensely blue chalcedony colored by copper-rich chrysocolla, prized as the most valuable of the blue chalcedonies.

Ancient wood whose organic tissue has been replaced by silica, preserving the grain, rings, and structure of the original tree in stone.

A prized Oregon picture jasper from the Deschutes region known for soft scenic landscapes in cream, tan, and blue-gray.