In-laws are often vilified, but since Hali married Olivia's brother, the two have shared more than the Thornhill name. "We have very similar taste; people even think we look alike," Olivia says. "And our jewelry is a true representation of ourselves: Classic fresh design without a lot of bells and whistles and driven first by color. I could never do Liv Haley without my sister-in-law."

The two women make a formidable pair: Olivia is a former award-winning wardrobe stylist and Hali is a gemologist who at

one time ran the diamond department for Canada's answer to Tiffany & Co., a fine jewelry company called Burke's, and then left to make custom engagement rings and other pieces. "Even as a kid, I collected gemstones," says Hali, who now collects jewelry books from bijoux design houses like Cartier and more esoteric European brands.

During a Thanksgiving with the family, the women decided to make a go of creating their own line, partially based on Olivia's unsuccessful quest for the perfect "refined, not Arizona" turquoise ring, and presented their first full collection in October 2011. They're both Canadian and Hali lives in Vancouver, but they based the company near Olivia's Santa Monica home, grateful for proximity to the jewelry manufacturing haven of downtown Los Angeles.

The distance initially was challenging, but Olivia and Hali send inspirations such as vintage photographs or buttons back and forth. Together, they troll gem shows for unusual stones that they render both high-end and wearable in settings such as silver or 14-karat gold with diamonds. "We're using fine semi-precious stones that are super high-quality and hard to find," Olivia says as Hali nods. "We use a lot of pink and white opal for summer or even winter white. We're really drawn to chalcedony, turquoise, orange aventurine and Australian green chrysoprase, which can be a milky or apple green. There's only one working mine for it."

Most recently, they've incorporated dark blue and gold-flecked lapis, chocolate brown agate, corrugated quartz with gold strands throughout and peach, chocolate and grey moonstone. They've expanded their large-bezel pave collection too.

Yunnie Morena, co-owner of Fred Segal Couture, was impressed and picked up the collection. "I was attracted to Liv Haley because of its clean, modern lines, which give the pieces longevity," Morena says. "Most people are looking for wardrobe staples that they can keep forever. These are super timeless and classic. The earrings with bright colorful stones are selling especially well for fine jewelry because color is so big right now and this is a way to get that pop, but know that you're still not buying some one-hit wonder. You'll wear them forever."

Celebrities have flocked to the jewelry, with Elizabeth Banks photographed wearing it on the cover of Redbook magazine's June issue, Ellen Kemper sporting it on"The Ellen DeGeneres Show,"the cast of "Gossip Girls" decked out on the show's season finale and star stylist Rachel Zoe pulling it for her clients.

As the two Thornhill women collaborate, their relationship continues to grow.

They feel they have the best of both worlds as a family business, which garners them invaluable support and enthusiasm. "I talk to Hali more than any other person on this Earth," says Olivia. "But I think because we're sisters-in-law as opposed to sisters, there's a boundary there. Trust me, we have had some blowouts, but we won't be completely obnoxious like you might with a blood relative."

Hali adds, "We can't let things bottle up or it's going to rock the entire family, so it pushes us to communicate."

Prices range from $85 to $4,500, and the collection is available at Fred Segal and at http://www.livhaley.com.

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