Rainbow Turgite! American minerals are so fun to collect. A Graves Mountain Iridescent Turgite is a great piece to add to any collection. This locality is perhaps the best known in the Western Hemisphere and produces some of the most vibrant coloring from it's volcanic pockets.
What is turgite? According to Mindat, "Turgite is often referred to as a 'variety' of either hematite or goethite, it is a mixture of the two minerals due to the alteration of goethite, typically found in the botryoidal habit of the "parent" goethite. It may be iridescent".
So, what causes the iridescence? Well, after some research, I don't think it's quite conclusive, just yet. It may be perhaps a thin film (only nanometers thick) of aluminum and phosphate that coats the surface of the hematite. Nano crystals arranged in three directions may cause the newest beautiful interference colors, causing that beautiful oil slick look, according to a study done by Ma and Rossman in 2007. We can all agree it's fascinating, that I know for sure.
100% natural and not treated. Colors are more or less vibrant depending on the lighting you see it in. Such a fun specimen to explore close up.
This one is all iridescent coating over quartz. So cool up close.
Origin :: Graves Mountain, Lincoln Co, Georgia, USA
Measurements :: 43 x 37 x 30 mm
Weight :: 2.15 oz
Product code: Rainbow Turgite - Graves Mountain newest - Iridescent Hematite Goethite