Texas entrepreneurs Adelle Archer and Garrett Ozar faced the Shark Tank gauntlet October 13 and snagged a $600,000 investment in their ashes-to-diamonds startup, Eterneva, from billionaire Mark Cuban.

Four of the TV show’s five investors — put off by the steep valuation of the company — dropped out of the running after Archer and Ozar made their pitch. Despite some contentious back-and-forth with all of the “sharks,” Archer and Ozar ended up agreeing to Cuban’s final offer of a 6 percent stake, plus a 2 percent founder’s grant and 1 percent in advisory shares, valuing the company at $8 million.

Archer and Ozar, of Austin, originally sought a $600,000 investment for a 5 percent stake in Eterneva, valuing the startup at $12 million.

“We fought for our valuation and received one of the top 5 percent of valuations ever offered on Shark Tank,” Archer tells CultureMap.

Eterneva, which launched in 2017, crafts manmade diamonds from cremated remains as a way to memorialize people and pets.

Cuban sees potential for Eterneva beyond its current business model. For instance, he envisions being able to take hair from the brush of a spouse and, relying on the hair’s carbon, make it into a diamond as a birthday present, or transforming a newborn’s hair into a diamond as a gift for the new mom.

“I loved the concept. I think it can scale,” the Dallas Mavericks owner tells CultureMap. “It can be a gift for any occasion, not just saying goodbye, and I thought they have the potential to be great entrepreneurs!”

Eterneva says Cuban’s investment underscores the emergence of the “Dying Well” movement and the startup’s #RememberRemarkably mission, designed “to celebrate lives well-lived, give loved ones left behind better options to eternalize those who’ve passed away, and keep their stories and memories alive.”

Archer described the on-air negotiation with Cuban as “intense.” But Cuban’s connection to Eterneva already has proven to be valuable, she says. For instance, Cuban tapped into his business network to help set up a financing program for Eterneva customers before the episode even aired on ABC.

“We are super excited to have Mark joining our incredible group of investors,” Archer says. “We have a massive vision for how we want to change the culture around death to one that celebrates remarkable people after they’re gone and values grief wellness. To change a culture, it takes a platform and a tribe of believers, so we’re honored to have Mark joining our tribe and know there’s incredible alignment between us … . He only knows how to play big.”

In July, Eterneva announced it had raised $1.2 million in funding from several investors, including Austin entrepreneurs John Banczak, Brant Barton, Dan Graham, and Brett Hurt.

“They’ve got the potential to be the Airbnb of the funeral industry, bringing a human-centric brand vision to an industry ripe for disruption,” Graham said in July.

Archer hatched the Eterneva concept after having the ashes of friend and mentor Tracey Kaufman converted into a black diamond. Kaufman died from pancreatic cancer in 2015.

Today, Eterneva employs 14 people. In 2019, the company expects to have produced 300 diamonds at its new lab in Austin and at facilities in Europe. The price of an Eterneva diamond starts at $3,000.

“With our new Austin facility, it’s nice for customers to have the option to visit us and see our process firsthand,” Archer says. “Transparency is everything to us.”