As a knapper I use various terms that usually work with archaeological jargon.  This is the case when discussing raw materials.  However, the terms I use don't always conform to 'proper'scientific geological terms.  Sometimes they do and sometimes they don't. There is no accepted geological terms in any case and there are many disagreements amongst geologists.  As an example, most geologists distinguish between quartzite (metamorphic) and silicified sandstone (sedimentary).  Archaeologist frequently do not make this distinction and call silicified sandstone quartzite; occasionally metaquartzite.  I do make this distinction because there is generally a difference between the flaking qualities of these two stone types.  In this case I side with most geologists.  However, I also use the term jasper, which tends to be discounted by geologists,because of the special texture the term connotes. I use stone type terms a lot in my descriptions and it becomes cumbersome and a waste of space to each time spell out the entire descriptive name, especially when used in image captions.