Gold in quartz. Dolan Springs, Mohave Co., Arizona, USA.  photo Heritage Auctions

It's the middle of winter in 1989 and Bud Guthrie was getting tired of freezing down in the Arizona canyon bottom east of the Colorado River, waving his "gold bug" metal detector like a scythe over the rocky ground and finding ... an occasional spent bullet. The south side of a nearby hill seemed to be getting a little more of the weak sunshine and might be just a tad warmer. Clambering up the hillside, he swept the open areas between the desert scrub bushes and was rewarded with a beep from his detector. Could be a can lid, could be another bullet. Whatever it was, the only way to find out was to dig. He started working carefully down through the mingled rocks, gravel, and soil next to a bush: six inches down - nothing. He ran his detector over the hole - still getting a signal. Digging down a foot - still nothing. He repeats the sweep - still getting a signal: this is starting to get puzzling - back to digging. Now Bud's down around 16 inches and suddenly runs into something solid. He peers down into the hole, brushes away some loose dirt covering the object and spots the first gleam. By God! It IS Gold! Looking to find the extent of the chunk, Bud alternates between digging, scraping and brushing, until he locates the edges of the thing. He finally succeeds in loosening the mass and pulls it free. This is BIG!! And damned heavy too! There's Gold showing all over - no wonder he was getting a signal from over a foot down. Now he's got something to take home to the folks in Helena, Montana.

Bud Guthrie never found another nugget quite like 'Fred': his name for this 70+ ounce monster of a nugget. After being reassured that it would be safe from "unauthorized withdrawal", Bud allowed it to be placed on display at a local bank in Helena, where it remained on exhibit for a number of years. Since its discovery, the big nugget has graced the covers of numerous magazines, copies of which are included with the lot. The present owner acquired it and decided, based on the serious weight of the nugget (estimated at 60+ ounces of contained Gold), that it would be a good idea if some of the gray-white Quartz mixed in with the massive gold was removed to make the Gold more visible. This task was entrusted to a professional preparator who seriously improved its visual impact. Before and after photos are included in the accompanying data package. The Gold has been exposed so that the specimen can be viewed from 360 degrees. With the Quartz removed, a large quantity of the rich high karat gold is clearly visible. The Gold is semi-crystalline with a strong sculptural quality.

As an extremely large Arizona Gold, with documented provenance, it was invited to be a showpiece at the special Arizona Centennial exhibit at the world famous Tucson Gem & Mineral Show. The Copper medallion that was awarded documents its participation. Overall measurements are 5½ x 3½ x 3 inches (14 x 9 x 7.6 cm), overall weight is 70.5 ounces troy, and it has a custom labeled base. It is in excellent condition.

Estimate: $300,000 - $350,000.

Heritage Auctions. 2012 May 20 Natural History Signature Auction- New York