Lucara demonstrated sales at $179 a carat in July and $257 a carat for the sales in September.
For the reporting period the company produced 91,400 carats from 594,000t ore milled at the project.
The Africa-focused company had initiated commercial production at its Karowe diamond project in Botswana on 1July 2012.
Lucara president and CEO William Lamb said that the firm is focused on performance and cost control, which resulted in a cash operating margin of 46% for its September sale.
"While the rough diamond market remains challenging, we are pleased with Karowe’s pace and stage of development and we continue to improve production while maintaining our outstanding safety record with zero lost time injuries this year," Lamb added.
