(IDEX Online) - Southstone Minerals reports further discoveries of very large and high-quality diamonds at its alluvial Oena mine, in South Africa.Output for Q3 (March to May) was severely impacted by coronavirus and an enforced five-week shutdown, down almost two thirds on the previous quarter.But the Canada-based junior miner said it had recovered 23 stones over 10 carats from the 8,800-hectare mine in Northern Cape Province (pictured). The most expensive was 35 carats and sold for $535,000 ($15,286 per carat).Other highlights included stone sized 52.62 carats (sold for $127,975), 44.25 carats (sold for $243,000), and 37.03 carats (sold for $188,962). Production for Q2 totalled 588.14 carats (77 diamonds, yielding an average of $1,942 per carat. For Q3 production was down to 215.78 carats (35 diamonds, yielding an average of $2,001 per carat).