ammonian

from The Century Dictionary.

• . Pertaining to Ammon, or to his temple in the oasis of Siwah in Libya.
• Relating to Ammonius, surnamed Saccas, of Alexandria, who lived early in the third century, and is often called the founder of the Neo-platonic school of philosophy, his most distinguished pupil being Plotinus.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective mineralogy Describing minerals that contain ammonium cations