New vintage black Austrian lead crystal flower earrings

New vintage black Austrian lead crystal flower earrings 10 facets. Hypoallergenic posts. C. 7 mm in diameter. Swarovski crystal entered the US market in the late 70s (Wikipedia) and Austrian lead crystal (which is related) was very popular soon after. They were a pretty, faceted, and cheaper alternative to natural gems and artificially created cubic zirconia then. These are from Canadian buyers in the 80s.