The problem is how you define "richest". There are many, many mines where individual assays were many times higher than 2.44 oz/ton. I have personally collected assay samples that ran over 1,000 oz/ton gold - pretty stuff.
If "richest" means the most oz produced, the Ruby Mine is not even on the list.
So, what in the world does "richest" mean? It is a meaningless term and often used by scammers to impress investors who know nothing about mining.