New vintage black Austrian lead crystal earrings (costume)

New vintage black Austrian lead crystal earrings (costume) 16 facets. Hypoallergenic posts. C. 10 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.