US polished-diamond trading slowed in August, according to government data.

Polished imports slid 7% to $1.55 billion for the month, figures showed. Polished exports slipped 0.4% to $1.38 billion, meaning net polished imports — the excess of imports over exports — fell 37% to $176 million.

By volume, polished imports declined 19% to 735,000 carats, with the average price increasing 15% to $2,113 per carat.

Rough imports more than doubled to $33 million from $13 million a year ago, while rough exports grew to $124 million from $16 million. Net rough imports stood at negative $91 million, compared with negative $2 million a year ago.

The US net diamond account — total rough and polished imports minus total exports — fell 70% to $85 million.

In the first eight months of the year, polished imports dropped 5% to $14.8 billion. Polished exports declined 4% to $12.26 billion, and net polished imports retreated 11% to $2.54 billion. Rough imports grew 31% to $555 million, while rough exports soared 94% to $526 million, leaving net rough imports 81% lower at $29 million. The January-to-August net diamond account fell 15% to $2.57 billion.