The characteristic bright red color is due to the high pigmenting power of hematite, which masks the coexisting yellow of goethite (Torrent et al., 1983). Ferrihydrite also gives a red color to terra rossa (Durn, 2003).
Best Regards Paolina Santos
There are two essential minerals; hematite and geothite , but hematite is found in higher ratios than geothite. So Terra Rossa takes the red color.
Dear Mrs. Santos,
there is only one good answer of Dr. Towe. Not scouting the literature what might be there and speculating about the presence of this or another mineral but climbing up the latter of analysis from the good old field methods of magnetic susceptibility measurements through XRD, DTA etc.. and ending up with Moessbauer spectroscopy. Fe is a tricky element due to its ubiquitousness and its valence states. I will not start listing all Fe-bearing minerals common to the physical-chemical regimes under near ambient conditions particularly in soil sciences.
There are good textbooks.
With kind regards
H.G.Dill
As already mentioned there are some basic methods to identify minerals of Terra Rossa, but this will not document their origin, do they result from in situ rock weathering processes or from allochthonous erosion or a mix of both, etc... ?? I just wish to modestly propose some case studies addressing both the nature of iron ox. (generally dominated by hematite over goethite and/or ferrihydrite), and possible origin (among others) of Terra Rossa that is effectively debated
These papers among others may be useful for our knowledge in Terra Rossa mineralogy, and, another one if we wonder also about possible origin (among others) or minerals formation mechanisms of "Terra Rossa" mainly upon karstic limestones. Regards, A.B.
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering