The Lulo mine in Angola contains diamonds that are 54% more valuable than previously estimated, despite more than a year of resource depletion, according to the asset’s owner.
The estimated price of the diamonds in the mine grew to $1,246 per carat as of January 31, based on the latest modeling assessment, compared with an earlier estimate of $806 per carat in October 2015, Lucapa Diamond Company said in a statement on Monday.
During the 15 months between the two tests, the company mined and treated about 220,000 bulk cubic meters (bcm). It also carried out exploration, sampling and trial mining of existing and new alluvial blocks.
Total resources at the mine increased 10% to 606,600 cubic meters during the period, the company added, projecting that alluvial diamond mining would continue for more than four years at a rate of about 20,000 bcm per month.
Rough-diamond sale prices from the mine have exceeded the original resource estimate, with Lucapa garnering $2,983 per carat in 2016, the company pointed out. The standout find was a 404-carat rough diamond, which it extracted from the mine in February 2016 and which sold later that month for $16 million, or $39,580 per carat.
The report follows Lucapa’s announcement last week that the resource estimate for its newly acquired Mothae mine in Lesotho was $1,063 per carat.