LONDON – It’s been a surprisingly ugly year for most diamond companies.

Shares of small producers, mainly focused on mines in southern Africa and Canada, have tumbled more than 30% during the past year and each company seems to be embroiled in its own mess.

The issues range from mine setbacks, political fights and low prices for certain types of stones. The volatility is normal for such a speculative corner of the industry, but the losses are surprising since rough-diamond prices have held up relatively well.

“If you look at diamond stocks this year, performance has been very poor,” said William Lamb, chief executive officer of Canada’s Lucara Diamond Corp. “Everybody has been kicked.”

PETRA DIAMONDS
The largest of the smaller producers, Petra Diamonds has been hit particularly hard, with the shares down 38% in the past year. Workers went on strike in South Africa earlier in September and the company missed production goals.

The company was also involved in a dispute with the Tanzanian government over diamond shipments for most of this month. It briefly halted production in the country and the government confiscated a diamond shipment on suspicion it was undervalued. The shares started to rebound last week as Tanzania said it would allow Petra to start exporting again.

GEM DIAMONDS
Gem Diamonds sank 34% in the past year. The company closed and put up for sale its new mine in Botswana following a slump in small gem prices.

LUCARA
Lucara also produced less than expected and took more than a year to offload the biggest diamond found in more than a century -- eventually at a lower price than anticipated. The stock slumped 38% in the past year.

FIRESTONE, MOUNTAIN PROVINCE
Newer producers, Firestone Diamonds and Mountain Province Diamonds, also stumbled. They have ramped up output, but stones sold for less than expected.

The diamond industry is dominated by two giants, De Beers and Alrosa PJSC, and several companies that are a fraction of the size.

It’s hard to tell how De Beers, a unit of Anglo American, is faring because the miner is famously secret about its dealings. Alrosa shares are down only 5% in the past year.

Lucara’s Lamb said diamond firms have taken too much of a beating.

“There’s definitely this oversold status with the diamond market,” he said. “I’m waiting for the point where everybody starts to realize that the diamond sector has actually been ignored and the investment opportunity is actually quite significant.”