The sale also included a second small 0.64 carats blue diamond, which sold for $24,500 at $38,282 a carat.
All 52 lots offered for sale were obtained from the company’s fully-owned Karowe mine in Botswana.
The lots contained 56,982 carats of diamonds and were sold for an average price of $300 a carat generating $17.14m in gross proceeds, said the company.
Lucara president and CEO William Lamb noted that this is the fourth sale of Karowe diamonds for Lucara.
"The value received for the exceptionally rare blue diamond has added significantly to the sale.
"The occurrence of the two blue diamonds sold confirms the excellent quality of the resource at Karowe," Lamb added.
Lucara will sell the last of the 2012 Karowe diamonds in December with an estimated 57,000 carats sales volume.
