The price of platinum rose for a second day as protests continue at a South African mine where nearly four dozen people have been killed during a labor conflict.

Platinum for October delivery gained $37.90, or 2.6 percent, to end Friday at $1,473.10, its highest level since early July. It rose almost 3 percent on Thursday.

Thousands of workers walked off the job a week ago at the platinum mine northwest of Johannesburg. Its owner, Lonmin PLC, has closed the mine.

South African police opened fire Thursday on a crowd of striking workers at the mine, leaving 34 dead. At least 10 others have been killed in the past week, including two police officers and two mine security guards.

Lonmin is the world's third largest producer of platinum, which is used in a variety of products, including automobile catalytic converters, spark plugs and computers. It also is valued as an investment, similar to gold, and used in jewelry.

Global platinum supplies remain plentiful. Demand has been weak, primarily because of slower industrial production in Europe where some countries are back in a recession because of a massive sovereign debt crisis.

There is speculation that inventories may tighten if the dispute continues for weeks, said George Gero, vice president at RBC Global Futures.

Platinum's price gain benefited palladium, which also is used in catalytic converters. September palladium rose $21.65, or 3.7 percent, to end at $605.10 per ounce.

Other commodity prices were mixed after a new report showed improving consumer sentiment. The Thomson Reuters/University of Michigan preliminary August index of consumer sentiment rose to its highest level since May. Most economists predicted a decline.

Trading volumes remained light, which is typical for August when many investors are on vacation.

Gold for December delivery rose 20 cents to finish at $1,619.40 an ounce, September silver fell 21 cents to $28.002 per ounce, September copper rose 3.7 cents to $3.4195 per ounce.

Benchmark oil rose 41 cents to end at $96.01 per barrel. Heating oil fell 3.03 cents to $3.0926 per gallon, gasoline futures dropped 5.57 cents to $3.0275 per gallon and natural gas ended down 0.5 cent at $2.719 per 1,000 cubic feet.

Wheat for December delivery rose 12.75 cents to finish at $8.945 per bushel, December corn fell 0.25 cent to $8.0725 per bushel and November soybeans gained 20.5 cents to $16.4575 per bushel.