Aphrodite's Tear.
One of the rarest gems in the world due to the scarcity of supply. There were only a few in the world... three, to be exact. And how did Hera know? Because she owned all those three through foul means.
People called it her obsession and her fondness for sparkly things. Owning all these gems granted Hera unimaginable control over the business. However, unlike what most people thought, she didn't treasure them as much as one would expect, considering what she went through collecting them. After all, she simply collected them because Felice, her mother, set her eyes on this gem and died.
Hera simply obsessed over them because she wanted to give them to Felice. Her mother might've died, but even so, Hera never stopped showing the affection and respect she had for her mother. Hearing Dominic set his eyes on the gem that killed Felice, she couldn't help but recall the bitter past.