TELL-TALE SAND GRAINS IN FORENSIC WORK
Case study 1: Sand, found attached to crates received at a customs location (US City) was the only evidence available to catch the crooks that were smuggling narcotics. The sand grains were sent to a chemical lab for analyses, who in turn called on me (geologist) for help. The sand was made up of sand-sized quartz and feldspar grains and recent shell fragments from a high energy beach environment'. This was not enough to go by. The next thing was to decipher the identity of the beach which could give us an idea of where the shipment was opened and the narcotics introduced into the crates. After inquiring about the route the shipment took and the ports it touched, a description of sand from the beaches of the various ports the shipment went thru were looked into. When the port matching the high energy sand' was identified, the criminals were apprehended.
Case study 2: A small sample of sand grains came to me through a chemical laboratory. The material was found in the helicopter engines of US armed forces deployed in the Middle East where pilots complained of frequent breakdowns. The only thing the maintenance crew found were some kind of sand grains in the engines. Upon examination with a microscope I found the grains to be made up of frosted quartz (some broken). The grain size was uniform and was similar to desert sand. Obviously, the sand grains from the desert area, where the helicopters were operating, got into the engines, and were grinding the engine parts and damaging them.
These serve as examples of how a geologist could solve crimes using a simple microscope or polarizing microscope along with good imagination and knowledge of the geology of different regions of the world.