Jagersfontein Mine ( /ˌjeɪɡərzˈfɒnteɪn/) is an abandoned open-pit mine in South Africa located close to the town of Jagersfontein and approximately 68 miles (109 km) south-west of Bloemfontein. Since it was first established in 1888, two of the ten biggest diamonds ever discovered, the Excelsior and the Reitz (now called the Jubilee), were mined from Jagersfontein. Jagersfontein is a kimberlite pipe, and a prime locality for mantle xenoliths.
The Earth Star Diamond was found at the Jagersfontein Mine. The diamond came from the 2,500-foot (760 m) level of the volcanic diamond-bearing pipe. The rough gem weighed 248.9 carats (49.78 g) and was cut into a 111.59 carats (22.318 g) pear-shaped gem with a strong brown color and extraordinary brilliance.