JOHANNESBURG (miningweekly.com) – Rough diamond prices are holding up, says RBC Capital Markets' equity research unit.

"Despite the expected summer slowdown in diamond demand, all indications are that rough diamond prices are quite resilient," RBC says.

In the lead-up to last week's De Beers sight and Gem Diamonds' tender, most of the news from the retail jewellery market was muted, and polished imports into Japan in July were down 36%.

"Add to that the return to the market of Alrosa, the Russian producer, and larger De Beers' sights, and it was surprising," the bank added.

That rough prices remained firm could, in part, reflect the need of the cutting and polishing factories to ensure they have sufficient stock for the Indian festival of Diwali and the important Christmas season in the US, the world's largest diamond market.

Diamantaires report that De Beers closed its seventh sight of the year with sales totalling from $450-million to $475-million, making August the largest sight so far this year.

It brings the Diamond Trading Company's (DTC's) year-to-date sales to $2,2-billion in RBC's estimation, compared with $4,8-billion this time in 2008, making 2009 the lowest seven-sight total in more than 20 years.

Nevertheless, the tightness of supply did see average prices up 5%, according to sight holders. Says RBC: "Our 2009 forecast is DTC sales of some $2,8-billion to $3-billion suggesting that one more large sight is in store before the year winds down."

Gem Diamonds' Letseng tender has closed on better-than-expected average prices of $1 588/ct for the 9 600 ct on sale and will probably mean Gem beats management's budget on a mostly-main-pipe parcel that was less attractive than the July sale.

Gem's year-to-date average is $1 415/ct compared with RBC's modelled price of $1 350/ct for 2009.

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