Align rock ontology with CGI vocabulary
Sub classes of rock are not logically coherent. the categorization of EarthMaterials in SWEET should be aligned with the CGI Earth Material vocabulary http://resource.geosciml.org/classifierScheme/cgi/2016.01/simplelithology
I'm getting a not found error on this link:

Does it resolve on your machine?
Try http://resource.geosciml.org/classifier/cgi/lithology
its also loaded into CORS http://cor.esipfed.org/ont?iri=http://resource.geosciml.org/classifierScheme/cgi/2016.01/simplelithology
I'll need to do some sleuthing to see where I came up with that URI for the vocabulary
also see http://cor.esipfed.org/ont?iri=urn:cgi:classifierScheme:CGI:LithologyOWL:201001 for an owl ontology based on the skos definitions.
@smrgeoinfo does this align with Loop3D at all?
The Loop3D GSO-RockMaterials (now public) are directly from the CGI SimpleLithology, with a simple skos to owl conversion described in the (draft) GSC OFR. We've added additional classes to handle altered rocks because of the requirements for Loop3D; a lot of those came from the cgi AlterationType vocabulary, with some definitions added.