AIM-listed diamond junior Botswana Diamonds believes sampling results from its Ontevreden kimberlite are indicative of a high grade kimberlite pipe.

Ontevreden is a new kimberlite discovery and is part of Botswana Diamonds’ Vutomi Joint Venture in South Africa.

Sampling at the Ontevreden kimberlite has found abundant G10, G9 and eclogitic garnets. This is typically seen in high-grade kimberlite pipes. Based on these results, Botswana Diamonds will look to drill the area later this year.

Ontevreden background

Having discovered a kimberlite pipe at Ontevreden, the next step was to ascertain if it was diamondiferous.  Samples from the pipe were analysed at the University of Johannesburg and produced abundant G10 and G9 garnets with a complimentary suite of eclogitic garnets.

This mix of garnets is typically seen in a high-grade kimberlite pipes.

This work followed detailed ground geophysics which identified a minimum size of 100 m x 70 m and whole rock geochemistry which characterised Ontevreden as a Group 2 kimberlite.  The next step is to drill the kimberlite and this is planned for later in the year.

The Ontevreden kimberlite pipe is close to Petra Diamonds’ Helam mine, which has grades in excess of 500 cpht and a diamond value of US$255/ct at a +1 mm bottom cut off.

“The exciting new kimberlite discovery at Ontevreden continues to entice.  Samples from the surface contain significant quantities of G10 and G9 garnets – high quality diamond indicator minerals frequently found at high-grade kimberlite pipes,” says John Teeling, Botswana Diamonds chairman.