FMF - Friends of Minerals Forum, discussion and message board

[Roger Warin]

The IMA reigns supreme in this reserved domain. There has been so much abuse that a watchdog was needed. This problem is, of course, limited to professionals. That much is obvious.
But professionals cannot ignore the presence of amateurs, who are a driving force in the discovery and preservation of samples. They are like gold panners gathering high-quality minerals. But amateurs are sometimes thrown off balance. Personally, I no longer know how to label this mineral.
If I ask a gemologist (professional) to label this green mineral, they will of course answer “Peridot.”
A mineralogist will tell me Forsterite-(Mg, Fe) because the color of the specimen is not pronounced. If the crystal had been very dark, they would have said Fayalite-(Fe, Mg), I think.
But in any case, the IMA concludes that this “solid solution” belongs to the olivine group. What is olivine? It does not appear in Fleisher's glossary.
It seems to me that the Glossary is funded more by amateurs than by laboratories.

The drawing I made in 2013 corresponds to the olivine of yesteryear. This drawing reproduces all the crystallographic forms present on this unnamed equant crystal.