lol I'm from China and never head of yin and yang scholar stones?
Okay I clicked on the wiki page and see that is what we call "miniature mountain stone" or "stone that look like mountains" (jia shan shi)... these as shown in wiki pages are used to decorate courtyards with trees, they can be a few meters tall to less than 1m.
and actually the Chinese for "scholar stones" (wen shi) refers to aragonite,