Silver mining has grown fantastically lucrative as this precious metals bull market charges onward. But due in part to the momentous short squeeze that in April sent silver prices soaring toward $50 per ounce, I anticipate windfall second-quarter profits that will give silver investors a taste of the earnings growth still to come.

First Majestic Silver (NYSE: AG) produced another 1.8 million ounces of silver during the second quarter of 2011, sauntering one step closer to its impressive 2011 target of 7.5 million ounces. The output yielded a precise match to those regal production numbers from the first quarter, although the company's powerful underlying growth momentum continues unabated.

While we wait for earnings results to trickle in from the sector over the coming weeks, a little fun with numbers (using First Majestic as a case study) can help Fools to anticipate the kind of quarter we can expect from the group. First Majestic's first-quarter net profit margin of 43% would qualify as an astonishing degree of profitability in many other industries, but for silver miners such feats have become commonplace. Silver Wheaton (NYSE: SLW), as a result of its unique business model, dominates in that category with a stunning first-quarter net margin of 82%.

As attractive as First Majestic's profitability was in the first quarter, it's about to get even better. You see, notwithstanding silver's headline-grabbing retreat from the April high, silver averaged more than $38 over the course of the second quarter. That's a 20% sequential increase and a harbinger of dramatic margin expansion for silver miners. We can use that price increase to forecast First Majestic's revenue at about $68 million and, so long as costs remained stable, an enhanced net profit margin that I suspect could yield net earnings of $31 million or better. That would mean a sequential earnings bump of nearly 30% between two quarters with identical production volume!

Now, I encourage Fools to apply the prospects for a 20% sequential increase in realized silver prices to their own favorite silver miners and adjust their own profitability expectations for the second quarter accordingly. Shares of silver miners suffered noteworthy weakness during the quarter, as indicated by a 16% decline for the Global X Silver Miners ETF (NYSE: SIL) over the period. With silver averaging 20% higher while the stocks drifted 16% lower, one is left to marvel at the potential opportunity presented by this unusual market divergence.

I consider First Majestic an excellent choice for investors as the company seeks to double output from its La Parilla mine starting next year. I believe Hecla Mining's (NYSE: HL) downturn has overshot by a wide margin, and Coeur d'Alene Mines (NYSE: CDE) is severely underpriced for a miner that's targeting 2011 production of 20 million ounces of silver and 250,000 ounces of gold! Alexco Resource (AMEX: AXU) picked a terrific time to enter commercial production, and junior miner Aurcana (OTC: AUNFF) expects to add a second silver mine by mid-2012. For each of them, and many more, I expect second-quarter earnings to reveal a powerful silver windfall.