Kim Kardashian's engagement ring cost her fiance $2 million

Kim Kardashian's 2.5 carat diamond engagement ring is reportedly worth almost half as much as Kim's Beverly Hills mansion and is valued at $2 million.

The 30-year-old beauty announced her engagement to basketball star Kris Humphries on Wednesday, and immediately after that, rumours started doing the rounds that the Lorraine Schwartz diamond ring set Kris back a huge sum of money.

"The ring is of the highest clarity and colour," Contactmusic quoted a source as telling TMZ.com.

The stunning piece of jewellery has impressed everyone, including Kim's younger sister Khloe, who joked it made her engagement ring from husband Lamar Odom look tiny.

She tweeted: "OMG I die for you! Kims ring gave birth to my ring! LOL but my ring is perfection! Its from my Lammy. (sic)"