3" Jack Straw Limonite after Marcasite 4.4oz Fortress Keep Mine MO Rare Intact For Sale

Up for sale from KeepsCache is a beautiful, hand-sized specimen of Limonite after Marcasite Pseudomorph from the Fortress Keep Mine in Jefferson County, Missouri.

​This piece features the classic and highly desirable "Jack Straw" crystal habit. The specimen displays an intricate, needle-like lattice of crystals that have been perfectly preserved through the pseudomorphic process. While Limonite has completely replaced the original Marcasite, every detail of the original "haystack" structure remains sharp and distinct.

​Measuring 3" x 2.5" x 2" and weighing 4.4 oz, this is an ideal size for a desktop display or a dedicated Missouri mineral drawer. Unlike many specimens of this type which arrive crushed or damaged, this piece is in a remarkable state, showcasing the true structural complexity that the Fortress Keep locality is known for.

​Specimen Details:

​Locality: Fortress Keep Mine, Jefferson County, MO

​Weight: 4.4 oz

​Dimensions: 3" x 2.5" x 2"

​Habit: Jack Straw (Pseudomorph)

​Condition: Intact