Locked in some of these intriguing, and often surprisingly attractive, minerals is some fascinating chemistry: sweden-borgite is sodium beryllium antimonate, bromellite is straight beryllium oxide, Langbanite itself is an appropriate manganese antimony silicate, and there are lead silicates and almost every combination of lead, chlorine and arsenic that you can think of.
During the last two years good trimerite and two beryllium minerals new for the locality, bromellite and helvite, have been found, the former as a 3.5-mm crystal aggregate in a calcite-filled skarn fissure, and the latter as crude flat crystals several centimeters across in narrow fissures in an iron ore skarn association.