One of the bronze sculptures stolen from the Johannesburg Art Gallery is worth about $16,000. Curators fear thieves sold it to a scrap dealer for a mere $250.

Prices for metals with industrial uses like copper — the main component in bronze — have been booming. And as the stolen bronzes fail to turn up at auction houses, galleries can only fear the worst.

“I understand that art will be stolen,” said Noah Charney, who founded a think tank called the Association for Research into Crimes Against Art. “But I get very upset when art is destroyed ... that is an irrevocable attack on beauty, culture and civilization.”

Bronze sculptures are only the latest target in South Africa: Days before U2 played a stadium in Johannesburg earlier this year, officials blamed copper thieves for power problems at the venue. Cable theft has led to service interruptions on the Gautrain, a sleek new South African light rail service.

At the Johannesburg Art Gallery, home to Picassos, van Goghs and Rodins, thieves stole a figure of a woman in mourning by South African master sculptor Sydney Kumalo. The Kumalo is one of a total of four bronzes taken in a robbery in January and another in September at the city-owned gallery.

A small bronze titled “A chair, a boat and a vase” by well-known South African sculptor Barend De Wet was wrenched from the facade of the national art museum in Cape Town in May.

“There’s a lot of very sophisticated (security) systems internationally that, unfortunately, we just can’t afford,” said Antoinette Murdoch, chief curator of the Johannesburg Art Gallery.

Murdoch said the city has promised her 1 million rand (about $125,000) to upgrade security, and she is seeking more from donors.