How a Salted Core Sample Killed a $4 Billion Mining Stock

On March 19, 1997, Bre-X Minerals' chief geologist Michael de Guzman fell out of a helicopter over the Borneo jungle on his way to meet auditors from Freeport-McMoRan. The Indonesian police called it a suicide. Bre-X's stock — split-adjusted CAD$286.50 the previous May — was still trading near its peak.

The story behind that price was the largest gold strike ever announced. Bre-X, a Calgary penny-stock outfit founded by David Walsh in 1989, had bought rights at Busang in East Kalimantan in 1993. By late 1995 the company was reporting hits. Consultant Kilborn Engineering, working from Bre-X's own cores, eventually estimated 71 million ounces. In a 1996 Fortune interview, exploration VP John Felderhof floated 200 million.

The samples were the problem. Indonesian pressure had forced Bre-X to take Freeport-McMoRan on as a development partner; Freeport drilled fresh holes a few meters from Bre-X's. On March 26, 1997 — a week after de Guzman's fall — Freeport announced "insignificant" amounts of gold. Strathcona Mineral Services reported on May 4 that the Bre-X cores had been salted with placer dust, some of it traced to local panners on the Mahakam River.

The stock collapsed to pennies. Roughly CAD$6 billion in paper market cap evaporated. Felderhof was acquitted in 2007. Walsh died in the Bahamas in 1998. De Guzman was never recovered intact.

What Canada got out of the wreck was National Instrument 43-101, the disclosure rule that now governs every public mining company on a Canadian exchange. Drill results have to be signed off by a qualified person, sample chains of custody are documented, and "resource" and "reserve" mean specific things. The rule exists because for a few months in the mid-1990s, the world believed a stack of salted core trays in a Calgary warehouse was the richest mine on earth.