The actress's close friend, jeweler Robin Renzi, designed necklace for the cause

When Julia Roberts heard about producer Gordon Gray and wife Kristen’s efforts to raise money to find a cure for their daughters’ rare and fatal brain disease, she called her friend jewelry designer Robin Renzi of Me&Ro to design a piece to benefit the couple’s foundation.

Julia Roberts necklace for charity

Getty, Inset: Courtesy Me and Ro Jewelry

The result — the gorgeous Gray Foundation Double Heart Pendant — is available now. One hundred percent of the net proceeds benefit the Charlotte and Gwenyth Gray Foundation, and its mission to raise the $10-12 million needed to fund research to find a cure for Batten disease.

“When I was asked to help the Grays in their fight to raise money for their daughters’ foundation, I was so moved by their story I felt I had to do something,” says Renzi. “I believe we all can help and I am so grateful to be able to donate 100% of the net proceeds to find a cure.”

Gray Foundation Double Heart Pendant

Courtesy Me and Ro Jewelry

Because Batten disease is so rare, there has been very limited research towards finding a treatment or a cure. The inherited neurodegenerative brain disorder has already onset in 4-year-old Charlotte, while 2-year-old Gwenyth has also been diagnosed.

“We’re just overwhelmed by how wonderful and supportive Julia (Roberts) has been,” the Grays tell PEOPLE in a statement. “With so many worthy charities vying for celebrity attention, we’re grateful she has been willing to use her time and relationships to benefit our foundation.”

Since the launch of the foundation, celebrities like Jennifer Lawrence, Gwyneth Paltrow and Angie Harmon have lent support at fundraisers and on social media.

Gray Foundation Double Heart Pendant

Courtesy Me and Ro Jewelry

The necklace is available here in recycled 18 Karat gold and sterling silver.

–Tiare Dunlap