Rachel Roy and Estelle have a strong mutual admiration society.

"I had seen her a few times and really liked how she took risks," Roy tells StyleList of the R&B sensation. "When I met her, I could see we had the same taste in jewelry with edgy, bold, messy stuff. She's a really hard worker, self-taught, and down to earth."

And Estelle's take on the designer? "I see how hard she works, and I respect her," she says. "She did her research on me and knew things people don't normally know. She's good people."

Last night, the duo took their shared love and limited-edition jewelry collection for Rachel Rachel Roy to New York City's Macy's Herald Square, where over 400 people turned up to meet Roy, check out the cool jewels, and hear Estelle perform.

The singer was happy to be among the fans. "I like to be out and see what people are buying and wearing," she tells StyleList. "Rachel has great customers. It's great to see people who weren't necessarily into me coming through this and my fans that weren't familiar with her learning about her."

The women's jewelry collaboration is super-edgy, with "bold" being the key description. Estelle literally started with pictures of things she liked, such as flowers, angels, and horns. The resulting jewelry is "a little tribal, a throwback, but glam," she says. "It's kind of something that catches you."

With some of the pieces already sold out, the collaboration's success is assured, but will it lead to more? "I think I'm just here for the moment," Estelle admits. "If I was to do anything else, I would have to study a little bit. It's a lot of work."

In other collaboration news, find out which jewelry designer just launched a ring collection based on "Alice in Wonderland."