Having worked in the jewelry business, I am well-versed in the seemingly endless ethical quandaries that arise between gemstone suppliers and a demanding public. These conflicts range in nature from child labor law violations all the way up to civil wars being fought by rebel governments using black-market stones to finance their operations. Several honest pathways exist for gemstones to come to market, yet layers of red tape need to be put in place to ensure that they come from an ethical source.

Most of us deal with issues like this in our daily lives. Perhaps not of the magnitude that the diamond industry does, but we're often left asking ourselves the following question: Is there anything wrong with wanting to do what's ethically right? Not at all. But should a company's line of business or its suppliers exclude it from your investment portfolio just because they don't fit a loose and ever-changing set of standards that determine what's right or wrong ethically?

Is choosing "green" mean?
Have you ever wondered what would happen if you threw socially responsible investing out the window? Here's my answer …

You'd profit!

I'm not saying you'll profit on every trade in what I'll call "sin stocks," but by simply including them in your field of investment choices you've broadened your scope of understanding of the business landscape and given yourself other avenues by which to boost your portfolio.

Since the barrier to entry in these industries is so high, due to the stringent laws that govern these industries, sin stocks often have considerable pricing power. Because of this, they can often provide a nice hedge against prolonged economic downturns.

Perusing sectors usually cast aside by social responsible investors, you can unearth some truly solid growth stories. After carefully searching through these sin stocks, I've uncovered two that present tempting valuations while offering solid long-term outlooks.

Bet on black
If I didn't know any better, I'd bet that Wynn Resorts' (Nasdaq: WYNN) roulette tables have only black numbers, because they simply do not know how to lose money. Because of its position in both Las Vegas and Macau, Wynn was able to weather the economic downturn with very few problems. Growth in Macau has remained strong, and gambling activity in Las Vegas is beginning to show signs of life.

In its latest quarterly filing, Wynn showed once again that even with the negative short-term impact of room remodeling at the Wynn hotel in Las Vegas, the company's key metrics continue to improve. Revenue per available room (revPAR) and occupancy rates both rose by 4% year-over-year. Wynn targets a more affluent crowd than some other casino operators, and I believe that's one reason why Wynn's bottom line results remain so consistent.

Of the major casino players, Wynn stands out as the most financially sound. Wynn has the flexibility to expand with just a fraction of the crushing debt that Las Vegas Sands (NYSE: LVS) and MGM Mirage (NYSE: MGM) have to shoulder, leading to stronger free cash flow. Though many think of Las Vegas Sands as the stronger growth story, when you compare Wynn's net debt of $1.2 billion versus Las Vegas Sands' nearly $8 billion in net debt, you probably are getting an idea why I feel Wynn is the safer play.

Brewing success
A company that doesn't worry me if I see some frothy financials is Boston Beer (NYSE: SAM), which you may know better by the brand it owns, Sam Adams. It is absolutely revolutionizing the craft brewing industry by keeping advertising campaigns relatively grassroots while expanding its product on a national and international level.

Despite staunch competition from Anheuser-Busch InBev (NYSE: BUD) and Molson Coors (NYSE: TAP), Boston Beer has been blowing these competitors' growth rates away. Boston Beer is at a definitive budgetary disadvantage to these behemoths, yet it has managed a 27% return on equity and a five-year compounded growth rate of 23%.

Even with a growing advertising budget, the company's balance sheet remains spotless, with $53 million in cash and no debt. Part of its success can be attributed to its prudent cash management. The other intangible that can't be overlooked is its image as the small guy competing against the beer giants. Its market share may be small, but with craft brewing on the rise, consumers are willing to pay up for Boston Beer's products.

Eyes wide open
The lesson here is that great investments can come in all shapes and forms. Emotions too often can cloud our ability to make clear financial decisions and we really shouldn't be limiting our investment choices simply because they don't fall within the usual scope of what we consider morally right. Keeping our eyes open for potential opportunities is to our benefit. Remember, a company will go up or down whether we think it's moral or not.

What do you think about socially responsible investing? Share your thoughts in the comments below!

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.