"Mookaite"

Item Description

According to mindat.org, "The term 'Mookaite' is an unofficial, locally coined name for a silicified porcelanite which forms in the weathering profile of a geological formation known as Windalia Radiolarite (WR), a Lower Cretaceous siltstone that outcrops over much of the Carnarvon Basin in Western Australia. Mookaite is variously, and incorrectly, described as chert, opalite, chalcedony or combinations of the three. From a strictly geological perspective however, Mookaite is best defined as a silicified type of WR whose silification is opaline to chalcedonic." For reference, Porcelanite is defined as "a rock, semi-vitrified clay or shale, somewhat resembling jasper, composed of mullite and other high-temperature silicate and oxide minerals". This stone is an attractive "Mookaite" stone with warm golden hues and an "Oval Cabochon" cut. One of the few and largest stones of this material that I have offered in the auctions.