The Diamond District of New York City is recognised across the world for its jewellery shops, diamond dealers and gemstone markets. However, in 2022, there were some prospectors who, instead of looking at the shining shops, focused on an unexpected location: the cracks in the sidewalk.Using brushes, hooks, buckets and portable vacuum cleaners, the prospectors sifted dust and debris from pavements in and around the Manhattan jewellery district to recover traces of gold, platinum, diamonds and gemstones left behind by years of trading and jewellery repair. According to the International Gemological Institute, some street prospectors say they can earn hundreds of dollars a day, with some reporting earnings of about $300What are the methods of sidewalk prospecting?It entails collecting a mixed composition of soil, dust, metal shards, and other residues found in pavements’ cracks and later separating them to search for any valuable contents. From reports on New York sidewalk prospecting, one example is Klesh, who began prospecting around the Diamond District at the corner of Fifth Avenue and West 47th Street.He uses a steel hook pick, brush, and vacuum to gather residues in pavement cracks and separates them to find heavy metals or gemstone shards. The residues collected through sidewalk prospecting are called “paydirt,” a mining term for material that contains valuable mineral deposits.Why do valuables end up on the sidewalk?The Diamond District is one of the world’s best-known jewellery-trading areas. It includes hundreds of jewellery shops situated around West 47th Street, Fifth and Sixth Avenue in Manhattan, and it specializes in the trade of diamonds, gems, and precious metals.Because buying, selling, repairing and processing jewellery happen in such a compact area, small traces of valuable material can sometimes end up in street dust. Identification of the materials, however, is not always easy. According to the Gemological Institute of America (GIA), it is often hard to identify what kind of stone you have – a natural diamond, laboratory-made diamond, or a fake one. According to GIA, some special devices are often needed because sometimes diamonds cannot be recognised by just looking at them.
This residue, known as paydirt, contained traces of gold and diamonds. Valuables ended up on the sidewalk due to extensive jewelry trading and repair activities. Image Credit: Wikimedia Commons
Gold extraction science from soilThere are many scientific concepts behind the extraction of metals from the soil, including gold extraction science. Gold is an element that has high density, making it possible to use its properties for separation using gravity separation techniques.According to the US Geological Survey, the dense nature and stability of gold cause it to deposit in certain places, and hence, it can be separated using gravity separation techniques from other materials of lower density. Street prospectors use the same principle but on a much smaller scale in order to find dense material from soil deposits.Urban treasure hunters beyond New YorkThe hunt for useful and valuable items in urban settings does not stop at New York alone. Metal detecting, recycling and urban scavenging are practiced by people all around the globe in their search for useful and valuable objects.The distinctive feature of this activity is that ordinary urban dust may contain material linked to jewellery making. Although searching for diamonds and gold in the sidewalk cracks may seem like a treasure hunt, valuable materials are not so easy to recover.It takes patience, skill, and the capacity to find any valuable material amid the tons of waste. The Diamond District hunters’ tale shows one of the peculiarities of city living, as amid millions of footprints and layers of urban dust, some valuable items may still remain unnoticed.