Mineral description : Olivine serie

Olivine from Malangen, Norway.

Olivine is not considered a single mineral any longer. It is the name of the serie made up of
fayalite ( (Fe,Mg)2(SiO4) ) and forsterite ( (Mg,Fe)2(SiO4) ).

Some references are considering only the purer endmembers of the series as fayalite or forsterite, the intermediate interval (10-90%) is called olivine.
I have made a page for localities with olivine, since many reports only talks about olivine and I don't have any analyse results to decide which mineral was found.

Localities A common mineral, for example in the NRM database there are 223 references (plus fayalite 31, forsterite 13). I'm only going to name some localities which I don't know the ratio of fayalite / forsterite.
Sweden :
  • In the Åsby diabase, Älvdalen area, Dalarna. As cm sized individuals together with feldspar and pyroxenes.
  • In the diabases of Skåne, especially around Höör. Up to 3 cm light green aggregates.
  • Taberg, Småland.
  • Lermon, Frostviken. Jämtland. In the soapstone quarry, sometimes even as crystals.
  • Stavsäter iron mine, Alnön, Sundsvall, Medelpad.
  • ... plus a number of other localities.
Norway :
  • Åheim. Olivine is mined here and both peridotite and crystals are being found.
  • Björkedalen.
  • Norddal.
  • Tafjord.
  • Hornindal.
  • Gurksöy.
  • ... plus a number of other localities.
Finland :

To silicate index.
Mineral group index.
Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.

axelsson@acc.umu.se
To my homepage.
Last changed : 2001-02-15