Rare Margarosanite, Franklin, New Jersey

Contributed by: Michael Crawford
minID: F2C-TY0
Date: Apr 21st, 2026
Locality: Franklin Mine, Franklin, Sussex County, New Jersey, USA (See on Mindat)
Size: 32 x 25 x 79 mm
Weight: 106 g

Description:
Margarosanite is a rare calcium lead silicate mineral that shows a beautiful short wave fluorescent response that ranges from blue/white to pastel shades of purple, pink and lavender. For these reasons it is one of the most coveted (and expensive) fluorescent minerals. First discovered in the Parker Shaft of the famous Franklin mine, in Franklin, Sussex County, New Jersey, this remains the classic location for the species. Margarosanite is also found at some of the mines in Filipstad, Värmland County, Sweden, such as Långban and Jakobsberg. The example featured here is from the type location, the Franklin mine, in Franklin, New Jersey.

This stunning specimen features lavender to pink margarosanite, green willemite, red manganaxinite and tan-fluorescing prehnite above under shortwave UV.

Originally posted by Chris Clemens on Nature's Rainbows in 2019.