Copper - image 1
Copper - image 2
specimen video

Copper

Unknown Owner
An excellent grouping of thick robust large native copper crystals. This is complete all around and could display well from either side. In terrific condition. The specimen comes with an antique label from noted collector Fred Cassirer dating this piece to 1911. Label as seen at the end of the video.

Product details

Species
CopperAbout Copper →
SizeMiniature
Dimensions5.0 x 4.5 x 2.0 cm
Added on11/15/2025
Locality
USA, Michigan, Keweenaw PeninsulaRegional guide →

Known provenance

DateCollectorAcquisition price
05/2026Unknown Owner$670.00
—Weinrich MineralsNot disclosed

Learn more

Copper
Mineral guide
Learn about Copper
native copper with spinel-twinned crystals and arborescences; notable from Lake Superior, Itauz, Dongchuan, Corocoro, prized for color and localities.
Copper
Regional guide
Copper from Keweenaw Peninsula, Michigan, USA
The Keweenaw Peninsula is the classic native-copper locality: a place where copper was not merely an ore mineral locked in sulfides, but the metal itself—dense, malleable, and often sculptural—precipitated as copper, Cu, in billion-year-old volcanic rocks. For collectors, “Keweenaw copper” is a category unto itself. It can appear as wiry arborescent sprays, thick hackly sheets, crystal groups with sharp metallic faces, rounded glacial float nuggets, massive vein copper, copper-filled amygdules in basalt, and copper in conglomerate where the metal laces between volcanic pebbles.