Next up was the base. Looking at pictures, we realized the color of the stone was dependent on lighting. Nathaniel selected Tamiya buff (XF-57) as a good place to start.
Tamiya 81772 Acrylic Mini XF72 Brown JGSDF 1/3 oz - Walmart.com
XF-57 Buff Tamiya opaco
Tamiya Tamiya Enamel Buff (XF-57) 10ml - Kingdom of the Titans