Gold in Kalimantan: where it is and how it's mined

Kalimantan’s gold comes in two forms. Alluvial gold lies in river gravels, sandbars, terraces and old buried channels, mostly in West and Central Kalimantan, where people have panned it for generations. Primary gold sits in hard rock, mainly in an old volcanic belt that runs through Central Kalimantan into East Kalimantan.

Licensed gold mines on the island have been few. Small-scale digging, much of it without any licence, is common along the rivers. That gap between the law and what happens on the ground is the first thing an investor has to understand.

Alluvial and hard-rock gold

Alluvial gold has already been freed from its host rock by weathering and moved by water. It settles as grains, flakes and the odd nugget wherever the current slows. It’s worked from the surface: by panning, by sluices, by suction pumps on rafts that pull up riverbed gravel and by excavators on the banks. Entry costs look low, but the gold is spread thin and unevenly, and it’s hard to measure before you dig. Alluvial gold explains why it looks easier than it is.

Hard-rock gold sits in quartz veins and altered volcanic rock, left by hot fluids around volcanoes millions of years ago. In Kalimantan most of it lies in an ancient volcanic arc across the centre of the island, with the strongest mineralisation along a corridor running northeast. The two best-known deposits on it that became working mines are Kelian in East Kalimantan and Mount Muro in Central Kalimantan. A hard-rock project needs drilling, a resource estimate, a processing plant and several years of work before the first gold is poured.

Where the gold is

Reports of gold mining, licensed or not, cluster in a few places:

• West Kalimantan: alluvial gold along the Kapuas river system. Police operations and press reports keep naming Bengkayang, Landak, Ketapang, Sambas, Sintang and Kapuas Hulu.
• Central Kalimantan: workings along the Barito, Kapuas, Kahayan and Katingan rivers, and hard-rock deposits in the north. The people’s mining areas the ministry planned for the province in 2026 are almost all for gold, in Murung Raya, Gunung Mas, Kotawaringin Barat and Pulang Pisau.
• East Kalimantan: home to the closed Kelian mine in West Kutai. Mining in the province today is mostly coal.
• South Kalimantan: mainly a coal province, with small gold workings in places such as Tanah Laut.
• North Kalimantan: little gold mining so far, though geological work has pointed to alluvial potential around Malinau.

The Kelian mine

Kelian, in West Kutai, is Kalimantan’s best-documented gold mine. A foreign-owned company ran it as an open pit under a contract of work from 1992, and it averaged about 14 tonnes of gold a year. The pit ran out of ore in May 2003. The plant processed the stockpiles until it shut on 7 February 2005.

The closure is the instructive part. It followed a closure plan approved by the government. By December 2004, about 85% of the 1,192 hectares disturbed by mining had been rehabilitated, and the site was set to become protection forest. The mine’s years of operation also brought land and compensation disputes with local communities, including blockades in 2000 that stopped production. A hard-rock mine can be large and long-lived, but it ends, and the ending has a cost that someone pays.

Licensed mining and the rest

Since Law 3 of 2020, gold mining licences come from the central government. Small miners have one legal route: the people’s mining licence, inside a designated people’s mining area (see mining licences). Much of the digging uses neither.

The figures are rough but point the same way. A national police mapping reported in October 2025 counted 1,517 illegal mining sites across Indonesia, 133 of them gold sites in Central Kalimantan. In January 2026, West Kalimantan’s deputy governor put unlicensed gold mining in his province at about 70,600 hectares. The financial intelligence unit (PPATK) has named West Kalimantan among the regions where it suspects unlicensed gold mining and illegal gold trading.

For an investor, that means a licensed area may already have diggers on it. A gold project offered privately may be an unlicensed working with no legal claim to the gold. And gold bought locally may have no lawful origin, which matters to any refinery or buyer down the line. Illegal gold mining covers the penalties and how licence holders deal with it.

Where to start

Start with the licence, then the data. Check the licence against the ministry’s records, its stage and its expiry date, and find out whether people already work the ground. Ask for drilling results and a resource estimate signed by a competent person, not grab samples or a figure for “potential” (see gold resources and reporting).

Then look at the land around the deposit. Check the forest status of the area and who lives along the river downstream, since tailings and mercury travel with the water. For alluvial ground, ask how the gold was measured. A few rich pans say little about a whole river terrace.