The Precious Metals of the Platinum Group: A Historical and Modern Exploration

 

In addition to the well-known precious metals—gold and silver—there exists a rarer and more expensive category known as the platinum-group metals (PGMs). These include ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and platinum (Pt). While gold currently fetches around USD 88 per gram, platinum, ruthenium, and palladium are valued at approximately USD 30 per gram. Rhodium and iridium are more costly, reaching USD 165 per gram, with osmium being the most expensive at USD 1,600 per gram—20 times the price of gold.

Despite the high value of these metals, their production remains limited. In comparison to gold, which sees the extraction of 3,500 tons annually, only 150 kg of osmium is produced worldwide. Interestingly, platinum-group metals are typically byproducts of mining operations for gold, copper, and nickel. These metals play a crucial role in various industries, such as jewelry, electronics, dental medicine, and even in cancer treatments.

In Indonesia, platinum is considered a group B mining material and is classified as one of the 22 strategic minerals. PT Freeport Indonesia produces approximately 375 kg of palladium, 30 kg of platinum, 50 tons of gold, and 200 tons of silver per year. Government Regulation Number 26 of 2022 further encourages the production of platinum-group metals by offering the lowest tariffs, ranging from 2% to 3.25%.

The interest in platinum-group metals emerged in the late 19th century. While the first mining law of the Dutch East Indies, the Indische Mijnwet 1850, did not explicitly mention these metals, the revised version of the law in 1899 did. Section 1, Article 1 stated that landowners whose lands contained platinum, osmium, iridium, gold, and silver had no rights to these metals. Historical records indicate that platinum-group metals were already being studied and mined in the region.

One of the earliest reports on the presence of these metals in Indonesia came from Ludwig Horner in 1857. A member of the Natuurkundige Commissie voor Nederlands-Indië, Horner documented the discovery of platinum in Kalimantan during a visit to gold mines in Poelo-Ary (Pelaihari, Banjarmasin). He reported finding one part of platinum for every 10 parts of gold and speculated that Kalimantan could produce at least 650 pounds of platinum per year. For context, Russia was producing 1,100 pounds annually between 1824 and 1851, while the United States produced far less.

Subsequent reports, such as the Natuurkundig Tijdschrift voor Nederlandsch-Indië (1851), further confirmed the presence of platinum, along with osmium and iridium, in the gold mines of Tanah Laut, Kalimantan. In addition, a discovery by German chemist Wöhler in 1867 of a mineral containing 62.88% ruthenium and 5% osmium marked another milestone in the study of platinum-group metals.

Dutch geologist and volcanologist RDM Verbeek also contributed to the exploration of these metals in Indonesia. His research in the 1870s traced platinum-group metals to Tjempaka (now located 47 km from Banjarmasin in South Kalimantan), where they were found in a diamond mine owned by Beretti. Indigenous miners, using basic techniques such as panning, had long discarded these metals, unaware of their value. By 1870, some began collecting them, and further chemical analysis confirmed their composition. Samples analyzed by Böcking and Bleekrode in Germany contained significant amounts of platinum, iridium, osmium, and palladium.

Following these discoveries, mining operations in Kalimantan increasingly targeted platinum. The Regeerings-almanak voor Nederlandsch-Indië of 1898 records several mining concessions specifically aimed at platinum production. These included the Ban Pin San concession in Sambas, the Goenoeng Lawak concession in Martapoera, and the West-Borneo Gold Field concession, granted by Sultan Sambas to EL Gordon.

The mining of platinum-group metals, however, faced significant challenges. One of the main hurdles was the lack of facilities for testing and extracting these metals by individual elements. During the colonial era, identification and separation of these metals were carried out in Europe, unlike gold and silver, which were processed locally. This limitation hindered the systematic production and identification of platinum-group metals in the region.

Today, Indonesia continues to face similar challenges. The country lacks sufficient laboratory facilities to test platinum-group metals on a production scale, meaning testing must be conducted abroad. While large mining companies may be able to extract platinum, the cost of bringing in foreign expertise and equipment often outweighs the perceived benefits of such operations. Nonetheless, as platinum is considered a strategic mineral, its potential for becoming a significant commodity remains high if explored and developed more seriously.

In conclusion, the history of platinum-group metals in Indonesia dates back to the Dutch colonial era, with significant discoveries and mining operations recorded throughout the 19th and early 20th centuries. However, the extraction and identification of these valuable metals continue to pose challenges, both historically and in the modern day. Despite these obstacles, platinum-group metals remain a vital component of various industries and hold promise as an important strategic resource in the future.