[Aztlan] Tech. Vocab. for Changes in Stone...

[kim Goldsmith]

Hi All!

Been so busy I have hardly had a chance to check in - - hope you all are doing well.

My question is regarding technical vocabulary when referring to the changes undergone by stone.  I know next to nothing about this except for the fact that it happens.  For example, when metals rust out, I assume (perhaps incorrectly) that this is called "oxidation".  When (petrified?) wood opalizes, I assume this is called "opalization".

One thing I have seen here at Teotihuacan particularly applies to onyx and different greenstones.  Something happens to them which seems to change their composition that does not necessarily appear to be "erosion", i.e. surface weathering.  Seeing as these stones are not metals, does anyone know what the correct word for this transition/transformation would be?  I'd appreciate any input on this that anyone can provide.

We've moved into the Director's house at the Arch. Zone and don't have access to Internet there, so I won't be able to check the forum right away, but again please know that I appreciate everyone's efforts, and thank you ahead of time for your help!

Best,

KIM