Pair of 8-point glass knobs with antique brass bezel finish. At least 1 of the knobs has purple tinting from manganese. Manganese is one of the oldest glass additives and was used in small quantities to de-colourise (remove the green tint from glass to make clear) and in higher quantities to colorize glass. This method dates as far back as Ancient Egypt. Turns purple when exposed to UV for many many decade. May have some left over paint on the spindle/brass.