A Gold, Diamond and Obsidian Danish Brooch Circa 1980 The 14ct gold circular brooch off set from the centre with two gold bars, carre set with a square cut snowflake obsidian mounted above with a collet set diamond, designed by Gail Spence for Hans Hansen, Denmark, hallmarked. Note. The Hans Hansen workshop, located in Kolding Denmark, merged with Georg Jensen in 1992