Orthoclase pseudomorph after Leucite (rare locality) (ex Henry de Linde Collection)

Item Description

These pseudomorphs are some of the most interesting replacements in the mineral world in my mind due to the minerals involved. First off, you have a feldspar species (Orthoclase) replacing a feldspathoid species (Leucite). Feldspathoids are defined as rock forming minerals that are lacking the necessary silica to actually form feldspar. So in this case we have the lower silica bearing Leucite that was replaced by a higher silica bearing Orthoclase to create these cool pseudomorphs. The habit of the original Leucite crystals is a trapezohedron, as the crystal system for the species is actually cubic at around 900°C. You'll see Leucite listed as being tetragonal in habit because the actual crystal structure changes once the species cools below 700-600°C. With all that said, if you're a fan of pseudomorphs you definitely need one of these unique specimens in your collection, as they are incredibly rare to find on the market from Turkey (though they are found in other places in the world), especially in this size with such well-defined crystal faces. This piece is essentially a complete "floater" showing the textbook trapezohedral of the original Leucite, but has been replaced by cream colored Orthoclase all over. From the collection of Henry de Linde (March 21, 1923 – April 4, 2019) of Hot Spring, Arkansas. Henry was one of the most prominent figures in the history of Arkansas mining and mineral collecting. Along with being a miner, mineral collector and an amateur mineralogist, de Linde was one of the founders of the Coon Creek Association mineral club. He was the owner of several key localities in Arkansas including the Diamond Jo Quarry (on the south rim of Magnet Cove), the type locality for Delindeite, which was named in his honor in 1987.