Now that silver prices have slipped a couple of bucks since the start of 2011, and even larger-cap legends like Silver Wheaton (NYSE: SLW) and Hecla Mining (NYSE: HL) have shed more than 15% in little more than a month, silver's rising star may be pausing in our solar system one last time before resuming its stellar ascent.

The first thing Fools may discover when they examine the silver star through a telescope is that it's surrounded by a galaxy of high-quality equity prospects that may be hard to reach through conventional means. For most investors without direct access to the Canadian exchanges, a concerted foray into silver will lead through an asteroid belt known as the Pink Sheets.

Frustratingly illiquid, easily manipulated, and decidedly off the radar of securities regulators, these (most-often) unsponsored ADRs are something of a black hole in the investment world that few seem interested in exploring. In order to access quality small-cap silver producers like Aurcana Corporation or ECU Silver, many will have to settle for a proxy to the Canadian-listed shares -- a proxy perhaps best described as digital scrip.

First Majestic Silver (NYSE: AG) recently jumped to the big board, and the stock's trading volume has increased visibly as a presumed consequence. As NYSE Euronext (NYSE: NYX) EVP Scott Cutler pointed out in First Majestic's press release: "[First Majestic] and its shareholders will benefit from the deep liquidity and global visibility offered to Canadian companies cross-listed on the NYSE". But you don't have to command a $1 billion-plus market cap to benefit from a cross-listing. I have observed small-cap silver names like Endeavour Silver (AMEX: EXK) and Alexco Resource (AMEX: AXU) drawing noticeably more attention from investors and media outlets alike, as compared with their non-U.S.-listed competitors.

Of course, I believe that both Endeavour Silver and Alexco Resources fully deserve the relative fanfare they've enjoyed on the merits of their laudable achievements. Alexco has executed beautifully on its transition to producer status, while Endeavour Silver has combined ceaseless organic production growth with an uncanny knack for locating fresh reserves.

To some extent, my own misgivings regarding the nature of unsponsored ADRs on the Pink Sheets are outweighed by the strength of my conviction regarding the growth potential of select companies in the space. I personally own multiple Pink Sheet holdings, but I would much prefer to hold the real McCoy. I encourage Fools who share my displeasure with these unsponsored proxy vehicles to join me in contacting your favorite Canadian resource companies that are not listed on a major U.S. stock exchange, and encourage them to fast-track such a listing.