Lady Gaga's engagement to Taylor Kinney wasn't the only surprise she shared with her Little Monsters this week. The pop singer also let fans in on the personal touch Kinney added to her engagement ring.

On Tuesday, Gaga posted a photo of the back of her ring on Instagram. Written in diamonds on the band is "T♥S" -- the "S" for Stefani, her real name.

"My favorite part of my engagement ring, Taylor and Lorraine [Schwartz] designed 'T♥S' in white diamonds on the band," she wrote. "He always called me by my birth name. Since our very first date. I'm such a happy bride-to-be! I can't stop smiling!!"

The main stone is a huge heart-shaped diamond.

According to E! News, the weight is estimated at 6-carats and probably cost between $400,000 and $500,000. However, Schwartz hinted that it could be more.

"[T]he stone is big and quite beautiful, and actually more expensive than some of the estimates I have read," the celebrity jeweler told InStyle, although she would not reveal the actual price or size. "It's a challenge to get an excellent heart shape with perfections - the shoulders of the gem have to be totally symmetrical; Lady Gaga's is all that."

Gaga and Kinney got engaged on Valentine's Day. After the proposal, they celebrated at her family's Italian restaurant, Joanne Trattoria, on Manhattan's Upper West Side.