In one of the year's most ironic pairings of headlines, JPMorgan Chase (NYSE: JPM) has announced the opening of a new gold bullion storage facility in Singapore ... even as a New York Post article appeared over the weekend reporting a possible criminal investigation by the U.S. Department of Justice (Antitrust Division) into alleged manipulation of silver prices.

During a period when Fools don't know what to really believe about the reported holdings in some of the industry's key gold and silver bullion vaults, one mining company continues to hold the key to an immense underground vault of untapped, well-proven ores. Gold Fields' (NYSE: GFI) may be a little rough around the edges when it comes to sustaining production growth and preserving those all-important operating margins, but what the miner lacks in style, it attempts valiantly to make up for in substance.

With South African operations again plagued by tragic mine fatalities and persistently high production costs, Gold Fields turned in another disappointing quarter. Net income fell into a deep mine shaft with a 69% decrease to just $44 million. The company's production of 793,000 ounces remains well shy of the long-standing production goal of 1 million ounces per quarter. More alarmingly still, Gold Fields' cash costs climbed steeply from already elevated levels to reach $703 per ounce. Towering above an industry average for seldom-reported all-inclusive costs that are likely now trending beneath $700 per ounce, Gold Fields reported that key operating metric at an unnerving $1,003 per ounce. Ouch!

Providing a much-needed counterpoint to these disappointing results, however, Gold Fields continues to show encouraging results from exploration and development work. This bodes well for the miner producing enhanced shareholder value by the tip of the drill and the sinking of the proverbial shaft. As I once discussed with respect to my favorite mid-tier growth pick, Agnico-Eagle Mines (NYSE: AEM), the significance of near-term disappointments in production can be offset by an effective expansion of reserves through exploration of high-quality ores. Since investors seem to react far more predictably to swings in production volumes than to often-overlooked reserve expansions, successful explorers can quietly build real value for shareholders.

Already boasting one of the industry's strongest asset portfolios, with 81 million ounces of gold in reserves, Gold Fields indicated positive results from 2010 exploration work that telegraphs further reserve expansion forthcoming at the St. Ives, Agnew, and Damang projects. On the development front, Gold Fields expects to begin production at St. Ives' Athena underground mine during the second half of 2010 ... adding 100,000 ounces per year beginning in calendar-year 2011.

A scoping study is expected for the alluring Chucapaca joint venture with Buenaventura (NYSE: BVN) during the next couple of month, and just this week the pair announced a major new discovery at the site with an estimated resource of 5.6 million ounces of gold equivalent. Buenaventura easily earns this Fool's title as the busiest joint venture partner in Peru. In addition to scoping work at Chucapaca, the miner is eyeing a multi-billion-dollar development at Minas Conga with partner Newmont Mining (NYSE: NEM), and the Tantahuatay project with Southern Copper (NYSE: SCCO).

With work steadily progressing to ramp-up production at Gold Fields' South Deep mine, and the concerted move to offset limited South African growth prospects with increasing production from solid international assets, Gold Fields remains a rare kind of bank vault indeed. Would you step into the vault of this high-cost producer? Please share your thoughts in the comments section below.