Your cheat sheet to the season’s most important diamond jewelry trendsSure, diamonds come with built-in demand, thanks to the gem’s long-standing reign over the bridal ­market, but savvy merchants are always looking for ways to keep diamond jewelry collectors blissfully addicted. The best retailers know that the better the story behind the jewel, the more likely it is to sell. Here are five diamond fashion stories happening now and why you need to share them with your customers. The Cut: Baguette This lean, less-brilliant-but-chic cut is having a major moment. No longer are baguettes relegated to estate cases or used solely as accent stones. “Everyone loves baguettes, but no one wants to see them set in the old type of settings,” says Northridge, Calif.–based designer Suzanne Kalan, whose Fireworks collection of baguette-cut diamonds purposely set in uneven patterns a