Vivianite (notably "bent" crystals) Cuprite you almost never see specimens

you almost never see specimens available on the market

From the famous replacement ore body in the Camp Bird Mine

Federico Pezzotta

bi-colored modified crystals with rich purple "cores" and light greenish-blue exteriors measuring up to 1

and this particular piece is bigger

Vivianite (notably "bent" crystals) Cuprite you almost never see specimensA classic example of "bent" Vivianite in the form of a handful of sharp, lustrous, fine green color crystals with "sword" shaped terminations and minor altered sandstone. Vivianite is an incredibly soft mineral, and it can often bend to create uniquely twisted or distorted crystals unlike virtually any other species. Combine that with the fact that the crystals are notably gemmy, and you have a one of a kind miniature. Most of the crystals are