Sturmanite, ettringite, and charlesite exist in a series and often in the larger crystals there is a gradient of one t the other within the same crystal. Seldom is that so obvious as here, where the colorless charlesite, which is 95% of the material and crystals present, grades to slightly yellow sturmanite at the tips of the scalloped edges. Old material from the early 1980s. Crystals to 1 cm. Ex. Charlie Key Collection.