Nathan Harris, an opal merchant in Melbourne, was my first introduction to the finer points of a fine black opal, but my first sighting of one of these stones came earlier. I vividly remember my father and Ross Allan at Kozminsky marvelling over an oval example that they were designing a diamond surround for. What were they marvelling at? The opal displayed a small black section, miraculously shaped as the silhouette of a diving bird, and on this piece it was if it was diving into the fire of the opal. It was an extraordinarily rare formation of colouring.
Later, I would meet Nathan or “Nat” as he would invite us to call him. Nat was a well-known and respected jewellery merchant (he celebrated his 100th birthday in 2022) but he was an extremely cautious bidder and was almost always outbid at my auctions in the late 1980s, unless it was a fine opal. Inevitably, he would be the successful buyer of every fine black opal that came our way. In those two years or so, that was maybe three or four. Such is the rarity of the “fine blacks” as we’d often refer to them.
Nat also explained to me that the earlier set opals, that is those that are within a piece of jewellery, were certainly more bankable and desirable the longer they had been out of the ground without crazing. ‘Crazing’ is a condition that opals can be susceptible to where their water content can decline and then create fine cracks on the stone’s surface. As Nat taught me, if it’s been mined and converted to jewellery in, say, the 1930s and 40s, and it hasn’t crazed yet, it’s unlikely to craze and represents a strong and stable opal.
This is unquestionably the critical finer point in understanding what underwrites an opal’s value and stability. In my view, this makes the exquisiteness of a great flaming black opal all the more fascinating because it is a precious gem that needs to be cared for and understood in a quite different way to its rival precious stone family.
By John Albrecht, Managing Director & Head of Important Collections
Top Image: Black opal ring. Sold for $10,000
August 2026