Indium is extensively used in LCD screens and solar cells. It is mainly produced as a byproduct during ore processing. With ever increasing demand for indium and most of the production being restricted to a few countries new sources for indium are needed. In Sweden, the westernmost Bergslagen is the only area, which is known to exhibit minerals with essential indium. The indium mineralisations at Långban, the Linbom prospect, which are studied in this bachelor’s thesis show several trends. The most notable is the copper indium trend seen in sphalerite. A likely substitution based on similar ionic radii and charges is Cu1++ In3+ ↔ 2Zn2+.Usually when cassiterite is associated with similar polymetalic indium bearing mineralisations as at Långban there is also high concentrations in cassiterite. This has previously not observed in Sweden, however during this project concentrations were indeed found in cassiterite.