Most people think of gold in its refined state as a coin, a bar or a piece of jewelry. Few get the chance to see gold as it’s naturally formed.

On May 4, Heritage Auctions will offer in its mineral auction “The Lightning Bolt” – a nearly 10-inch-high formation of gold weighing 22.66 troy ounces.

The piece is from Mt. Monger Station, Western Australia, and its discoverers gave the piece its name due to its unusual form.

The catalog notes, “There is an increasing amount of evidence that some near surface gold is the product of biologically mediated deposition, involving plant derived compounds that assist in mobilization and deposition of metallic Gold.”

Supporting this theory, the description cites irregular cylindrical features running lengthwise down the piece, which Heritage notes “is very similar to material that accretes around tree roots in desert regions, where it has been associated with transport and deposition of Copper and Aluminum ions.”

The description uses a term familiar to coin collectors of gold coin by saying that the surface of the piece has areas of luster, with smooth and rough areas. Another thing that is of note to collectors of naturally formed gold is that it has a large surface area for its weight ratio.

With gold at around $1,300 an ounce, by weight alone it would have a “melt value” approaching $30,000. But to a collector, the value is much greater. The piece carries an estimate of $150,000 to $180,000.