Rock & Mineral Encyclopedia

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

Crazy Lace Agate

A Mexican banded agate famous for tightly swirling, contorted lacy patterns in warm reds, creams, and golds.

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

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

A vividly swirling banded agate from northern Mexico with intricate looping patterns in warm reds, golds and creams.

A banded variety of chalcedony quartz, famed for its colorful concentric layers and enormous range of patterns and colors.

Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.

A rare brown chalcedony containing thin iron-oxide layers that produce flashing, fiery rainbow iridescence like trapped flames.

Glacially transported banded agates found along Lake Huron's shores, typically small, frosted pebbles with red-orange iron banding.

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

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

A glacier-transported banded agate from the Lake Superior region, colored by iron into rich reds and oranges, and Minnesota's state gemstone.

A glacially transported agate found in Midwestern gravels, named for the Coldwater area, showing banded chalcedony patterns.