Sunarto, 41 years old, carries a load of sulphur out of the Kawah Ijen crater.

The air at the crater is thick with toxic volcanic gas, and miners often don’t use proper protective equipment.

Miners navigate difficult terrain while carrying 150-200 pound loads of sulphur.

A miner's headlamp cuts through the darkness and volcanic gas. Miners often begin their work at night before the sun's heat becomes too oppressive.

The blocks of sulphur mined from Mount Ijen are processed and used to manufacture a variety of products. While historically used in gun powder, today it mostly used for cosmetics and bleaching sugar.

Miners break up sulphur blocks inside the volcano's crater, and fill wicker baskets to haul back down.

Tourists explore the crater of Mount Ijen, which can see more than a thousand visitors per day during high season.

Forty-three-year-old Wito carves a flower from a block of sulphur to earn extra income from tourists.

Mount Ijen is famous for its blue flames, which are caused by the combustion of sulphuric gases and can only be seen at night.

Shrouded in sulphuric gas, a miner uses a metal pole to extract lumps of sulphur.

Gas rises from Mount Ijen's acidic crater lake.

Miners earn extra income by selling souvenirs made from the mine’s sulphur.

Bandi, 40 years old, processes sulphur in a crude factory in Tamansari Village. After being transported to the factory from the volcano, molten sulphur is ladled from the melting pots into carrying buckets.

Seventy-year-old Pak Suil processes sulphur in Tamansari Village. The liquid sulphur is spread on the floor to cool into sheets. Once hardened, it is broken into pieces and loaded into sacks. The mine produces 14 tons of sulphur per day, and much of it is exported to China and Southeast Asia.