Former Miss USA Scores Yellow Sapphire Engagement Ring

Former troubled Miss USA Tara Conner is adding more bling to her tiara collection ... she's got herself a sparkly new engagement ring.

We're told the lucky guy is writer and acting coach Dan Sanders-Joyce. Dan popped the question over 4th of July weekend while they were vacationing in Hawaii.

Tara is most infamously known as the Miss USA who got to keep her crown despite testing positive for cocaine 8 months into her reign. She's been sober for a decade.

As for the ring ... it's a 4.83 carat yellow sapphire from INTA Gems & Diamonds. We're told Dan chose yellow since they bonded over their struggles to recovery and the $50k stunner is suppose to symbolize their brightest days together.

Mazel.