Gem Diamonds reported a decline in first-quarter sales, marking a contrast after a stronger performance in pandemic-hit 2020.

Revenue fell 7% year on year to $43.9 million during the three months ending March 31, the company, which owns the Letšeng deposit in Lesotho, said in a trading update Thursday. Sales volume dropped 8% to 26,916 carats.

The slump in volume outweighed a 1% increase in the average price to $1,630 per carat. Prices of Letšeng diamonds reflected an improvement in market conditions, with five diamonds selling for more than $1 million each in the first quarter, the miner noted.

“Production from the mining mix was not as impressive as the second half of 2020, with fewer large diamonds recovered due to the [nature of the] areas accessed under the mining plan,” said CEO Clifford Elphick. “The mining mix should improve over the coming months as the richer parts of the satellite pit are accessed.”

Production rose to 29,010 carats from 26,110 carats a year ago, with the company’s 2021 output guidance remaining unchanged.

Last year, Gem Diamonds was one of the few major rough producers to record annual revenue growth, as sales grew 4.2% to $189.6 million. That helped net profit more than double to $24.3 million.