þungunarskimun

Þungunarskimun is an Icelandic term that translates to "heavy metal screening" or "heavy mineral separation." It refers to a geological and analytical technique used to concentrate and study dense minerals found in rock and sediment samples. This process is crucial for identifying and quantifying minerals that are often present in small quantities but can hold significant geological information.

The primary goal of þungunarskimun is to separate heavy minerals from lighter silicate minerals. This is typically achieved by using a liquid with a density higher than that of common rock-forming minerals, such as quartz and feldspar, but lower than that of valuable or indicator minerals. Common heavy liquids used include bromoform (density 2.89 g/cm³) and methylene iodide (density 3.33 g/cm³). When a sample is mixed with a heavy liquid, the lighter minerals float to the surface or remain suspended, while the denser minerals sink to the bottom.

The concentrated heavy mineral fraction can then be further analyzed. This analysis can involve petrographic microscopy to identify and describe the mineralogy, or it can be subjected to chemical analysis to determine elemental compositions. Þungunarskimun is widely applied in various fields, including mineral exploration (e.g., searching for gold, platinum group elements, diamonds, and rare earth elements), sediment provenance studies (determining the origin of sediments), and environmental geochemistry (identifying pollutant-carrying minerals). The technique allows geologists to focus on specific mineral suites that are often more informative about geological processes and resource potential than the bulk sample.