According to this website, there used to be an interactive version of that fictional periodic table:
However, that link is no longer functional because the site died. But we can access it through the wayback machine. The page is blank, but upon checking its source code, we can download the following Flash content, which is the interactive periodic table: periodiekklein.swf.
By using a software to run the Flash content, we can see the following:
Name: Red Stone
Source: Fullmetal Alchemist - Hiromu Arakawa
Specifications: Reddish stone. Ampifies the transmutation power of alchemists. Made with Red Water, a high-toxic liquid.
The Red Stone is also called the Philosopher's Stone in the manga Fullmetal Alchemist; although in this particular case, since Red Water is mentioned, it is most likely a reference to another kind of Red Stone from the 2003 anime, which is distinct from the Philosopher's Stone. HA is the author Hiromu Arakawa.
If you want to learn more about the other elements, you can download the file and run it either with a standalone Flash Player, or any browser based Flash Player (e.g. Ruffle for example).