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HDXRF Helping Law Enforcement Crackdown on Illegal Mining


Illegal mining operations in Indonesia cost the country $6.1B per year in lost tax revenues and license fees. The Indonesia Police Laboratory (Puslabfor) uses HDXRF technology in forensic investigations targeting unlicensed gold, silver and other precious metal mining on public and private lands. Over the past 2 years, hundreds of rock, soil and sludge samples from over a dozen potential sites have been surveyed to identify precious metal and other elemental content. Using this new forensic tool, Puslabfor can link seized materials to specific mining sites making it easier to disrupt illegal mining.


Forensic investigations for illegal mining require on-site sampling across many sites to find geographic matches with seized samples and processed materials. Traditional testing methods, like wet chemistry, require highly trained specialists and can be very costly. Outsourcing samples to a lab is not ideal due to long turnaround time which delays the investigation, high cost, and logistical issues like breaking the chain of custody for evidence.


Using HDXRF, Puslabfor is able to quantify the elemental composition of samples on-site, making it possible to quickly survey and discover links between field measurements and pre-measured contraband. The precision of the HDXRF measurement provides reliable ratios of elemental content that can be used as signatures for matching and identification purposes. Compared to traditional wet chemistry testing, HDXRF is much faster, more cost-effective, more efficient, safer and as reliable. Which is why many prefer HDXRF analysis, especially when working with dozens of samples that make lab-based measurements labor intensive and cost-prohibitive. HDXRF instruments are also very easy to use and do not require highly trained professionals to operate, allowing officers in the field with minimal training to produce court ready results.

Table 1

Element (ppm) Sample A Sample B Sample C
Au 357,494 554,358 983,053
Ag 24,800 5,357 16,131
Cu 2,807 80 471
Ti 26,803 ND < 155 ND < 118
Fe 46,032 ND < 56 ND < 48
Pb 312 ND < 73 ND < 21
Hg ND < 55 385718 ND < 67

Table 1 shows measurements of investigated samples using HDXRF to identify the precious metal content (Au, Ag, Cu) and lead and mercury contaminants. Sample A is from raw material that has been processed to concentrate the gold and heavier elements, typically by panning or sluicing, before the mercury-based refining process. Sample B shows substantially higher concentrations of gold compared to Sample A, with heavy mercury content from in-the-field refining operations. Sample C is from remelted jewelry based on the high purity of the gold, and lack of contaminating elements.

Over 850

hot spots in Indonesia

for illegal mining**


HDXRF technology has also been used to assess the environmental impact of illegal mining operations. With tailings containing elevated levels of Arsenic and Mercury, the legacy of site contamination from illegal mining activity will linger long after the miners have moved on to other sites. With ASTM D8064-16, HDXRF can be used to quantify heavy metal contamination in soil and sediment with levels of detection as low as 1 mg/kg.

“HDXRF is much

easier and a simpler

testing method than

wet chemistry.”

- Mrs. Astarini Endah,
Chemical Sub Department Head

Indonesian Illegal

Gold Mining Losses:

Rp 80 trillion per year

($6.1 billion)*


Rocksand Powered by HDXRF

Rocksand is a portable analyzer for applications such as soil, solid waste, water and plant measurements. Powered by HDXRF technology, Rocksand is the only solution with an approved standard test method for elemental quantification of heavy metals in the field. Rocksand complies with EPA 6200 for simple screening, as well as ASTM D8064 for quantitative analysis. This instrument delivers heavy metal detection and analysis below regulatory limits, particularly for elements like Cadmium, Arsenic, Lead and Mercury.

XOS is now offering Rocksand for rental in the United States – visit xos.com/RentRocksand for more details.

*Illegal mining causing over Rp 80t in losses, TheJakartaPost
**The Toxic Toll of Indonesia’s Gold Mines, National Geographic