Diamonds may be forever, but profits are apparently much more fleeting.

Take, for example, the case of jewelry retailer Zale (NYSE:ZLC) and its lackluster (sorry, couldn't resist) first-quarter results. The company reported a loss of $0.21 per share, down from a $0.17 loss in the same quarter last year, largely the result of a $9.2 million increase in SG&A (selling, general, and administrative) expenses that outpaced the $6.1 million rise in total sales. Also of note is the 0.9% decline in same-store sales, which management partially blamed on this summer's hurricanes and their timing -- Zale had to close a number of stores in the Southeast over Labor Day weekend because of the weather.

Put into proper context, this past fall quarter has been a difficult one for the industry.

But not all have suffered equally. Tiffany (NYSE:TIF) felt a bite in its profit margin from a rise in wholesale costs of precious metals, but still managed to eke out 4% growth in comps, despite difficulties in the Japan market. Internet competitor Blue Nile's (NASDAQ:NILE) margins were similarly hit, but much more so. (It's worth noting that Zale is in a better position than Blue Nile, since large offline jewelry retailers can partially hedge their raw material purchases with inventories, a bit like airlines buy their fuel. But if wholesale costs stay high and continue to climb, Zale certainly won't be immune, and the effect will eventually be reflected in the bottom line).

With the stock's price near its 52-week high, investors want to know whether Zale is ultimately in trouble. So far it doesn't seem to be. Competition from aforementioned sources has been heating up for a while, yet the company did not seem to notice -- it opened 23 new stores and stuck to its upcoming forecast of a 2%-3% climb in comps and 6%-7% revenue increase. That should give investors some confidence that analysts' predicted annual long-term growth of 12% still seems achievable.

Fool contributor Marko Djuranovic does not own shares in any companies mentioned in this article.