WINDHOEK, Namibia >> Dina Muhimba handles hundreds of diamonds every day in what she describes as a “no-mistake job.”

Muhimba, who sorts gemstones at the Namibia Diamond Trading Company, sits at a long table with colleagues, studying the cut, color and clarity of diamonds mined mostly offshore in one of the southern African nation’s biggest industries. She wears headgear with a magnifying lens and sifts through rough diamonds, lifting each with thumb and index finger in a meticulous process that is repeated for hours.

“Each stone has its own unique characteristics,” said 42-year-old Muhimba, who has been doing the job for 17 years.

Her work space in downtown Windhoek, the Namibian capital, overlooks the North Korean-designed national museum, a church from the German colonial era and hills on the horizon. Security is tight; workers avoid wearing shirts with pockets and must make sure small diamonds don’t accidentally fall into the folds of clothing.

The trading company, or NDTC, says it sorts an average of more than 1.3 million carats annually; diamonds go to local factories for cutting and polishing as part of an effort to benefit Namibians. The NDTC is a joint venture between the De Beers diamond company and the Namibian government.

Carmen Grimbeek, another diamond evaluator, said some diamonds with “impurities” are not jewelry quality and are set aside for industrial use, such as in the manufacture of saw blades. She said she liked the “specific energy” that diamond colors, including yellow and brown, emit.

Diamond mining in Namibia dates to discoveries around the coastal town of Luderitz during German occupation in the early 20th century. Many Namibians with a rural background would rather spend money on livestock than diamonds, but the culture is slowly changing, according to Grimbeek.

Muhimba said she can’t afford a diamond.

“Maybe one day I’ll get a husband who will buy me one,” she said.