Earnings season has, so far, been a mixed bag for most industries. But for gold and silver miners this is one for the record books.

One of the selling points of precious metals miners is that they're "leveraged to the gold/silver price", which means a small move in the price of the underlying metal produces a big change in a miner's profitability. This is bad when the metals are going down but potentially great when they're going up. And right now the math is highly favorable: Gold and silver are up from a year ago, so miners that produce similar amounts of metal at a similar per-ounce cost are generating big earnings increases. Some excerpts from recent quarterly reports:

Barrick Gold Earnings Jump 45%
Higher gold and copper prices pushed Barrick Gold Corp.'s third-quarter earningsup 45% to a record level, beating analyst expectations.

Barrick, which late Wednesday boosted its quarterly dividend by 25%, posted net income of $1.37 billion, or $1.36 a share, up from $942 million, or 94 cents a share, a year earlier. Adjusted earnings jumped more than 50% to $1.39 billion, or $1.39 a share, it said, beating the Thomson Reuters mean estimate of $1.35 a share.

Revenue increased 44% to $4.01 billion, ahead of the $3.88 billion analysts were expecting, as Barrick's realized gold price rose 41% to $1,743 an ounce.

Eldorado Gold posts 48% Q3 profit growth on record gold production
Eldorado Gold (TSE:ELD) (NYSE:EGO) (ASX:EAU) saw its third quarter results meetor exceed Street estimates on Thursday after it reported record gold production,higher selling prices, and lower operating costs. For the three months endingSeptember 30, the gold miner posted profits of $110.7 million, or $0.19 per share,up 48 percent from $74.8 million, or $0.13 per share, a year ago.

Revenues rose 71 percent to $326.1 million, from $190.3 million in the same period last year. Analysts polled by Bloomberg Businessweek had expected 19-cents per share in earnings, on $311 million in sales.

The company produced a quarterly record total of 179,195 ounces of gold - 18 percent more than it did a year ago. Total cash operating costs fell three percent to $397 per ounce, while selling prices rose 38 percent to $1,700 per ounce during the third quarter.

Kinross Reports Rise In 3Q Adjusted Earnings, Record Quarterly Revenue
Kinross Gold Corp. (TSX: K, NYSE: KGC) posted adjusted net earnings of $273.4million, or 24 cents a share, for the third quarter, the company said late Wednesday.This was up by 134% from $116.8 million, or 15 cents a share, in the year-agoperiod.

The company listed record quarterly revenue of $1.069 billion, a 45% increase over $735.5 million in the third quarter of 2010. The increase was the result of more ounces produced and an average realized gold price of $1,646 an ounce in the third quarter, compared to $1,190 in the third quarter of 2010.

Royal Gold Revenue Grows Again by Double-Digits
Net income for Royal Gold, Inc. rose to $17.2 million (40 cents per share) vs.$11.8 million (21 cents per share) in the same quarter a year earlier. This marksa rise of 45.3% from the year earlier quarter.

Revenue: Rose 42.2% to $64.5 million from the year earlier quarter.

The company has enjoyed double-digit year-over-year percentage revenue growth for the past five quarters. Over that span, the company has averaged growth of 56.4%, with the biggest boost coming in the first quarter of the last fiscal year when revenue rose 73.6% from the year earlier quarter.

Yamana Gold Announces Third Quarter 2011 Results
Production of 279,274 gold equivalent ounces (GEO) at cash costs of $94 per GEO.Gold production of 230,986 ounces. Silver production of 2.4 million ounces. Productionincreased 4% to 279,274 GEO. Revenue increased 22% to $555 million. Record adjustedearnings increased 63% to $190 million, $0.26 per share. Cash flow generatedfrom operations increased 57% to $330 million, $0.44 per share. Generated cashmargin of $1,603 per ounce, an increase of 36%. Cash and cash equivalents atSeptember 30, 2011 were $570 million, a 73% increase from the beginning of theyear. Cash flow generated from operations increased 66% to over $945 million,$1.27 per share, as at September 30, 2011. Dividend increased for the secondtime this year to $0.20 per share annually

Some thoughts

Comparisons will stay favorable for another couple of quarters and then get harder, as next year's gold/silver price is compared with August's parabolic spike. The sense that these growth rates are unsustainable might be one of the things holding back mining stocks in the face of great current earnings.

But if gold and silver just hold their current levels, the cash flow being generated by the strongest miners will allow them to 1) pay off debt and strengthen their balance sheets and 2) institute or increase dividends.

It's possible that a year from now the precious metals miners will appeal to both growth and income oriented investors. That's a lot of potential cash flowing into what is still a tiny sector.