Gold Crystal with Quartz, Marble Bar, Pilbara Region, Western Australia. Photo Heritage Auctions

As Gold specimens go, this one is quite interesting due to the evidence of its bi-modal origin. Part of the specimen shows distinct crystalline form, which can only result from sufficient free space for the developing Gold crystal to grow into or within. Other areas of the piece include rounded pebbles of Quartz that forced some of the Gold to form around them, a situation more typical of how most nuggets start. One edge of a "hoppered" crystal measures .63 of an inch (1.59 cm): quite sizable for a Gold crystal.

The specimen shows the deep, rich color normal for Aussie Gold and the included Quartz is a light, mottled rust color that complements the Gold well. It weighs 37.5 grams (1.205 ounces troy) and measures 1.25 x 1 inch (3.17 x 2.46 cm). [Scale: 1 inch, with mark at 1 cm]. Estimated Price: $18,000 - $22,000

Heritage Auctions. 2013 June 2 Natural History Signature Auction Session 2. Phone: 800.872.6467 - Email: Bid@HA.com