Talk:Greninger chart

This article refers to variables called g, d, x, y, s, q, m without saying what they are! It also refers to "zones" and "planes" in crystals. I don't know what those are and when I click on crystal I find a long article in which the words "zone" and "plane" do not appear!

Some explanation of these terms, or at least links to articles that explain them, should be here.

It also neglects to say who Greninger is. That should also be here. Michael Hardy (talk) 04:26, 19 June 2011 (UTC)