Thats a very simple way to determine which cards are considered spells
While I wouldn't recommend picking up packs looking for a copy of The One Ring for your Commander deck, the set has become an investor's holy grail - at least for those who bought in close to release
Though it was just short of receiving a grade of CGC Perfect 10, this example of Ancestral Recall is still the best example in the CGC Trading Cards Population Report with a grade of CGC Pristine 10 and sub-grades of 10 for Centering, 9.5 for Surface and 10 for Corners and Edges
According to official rulings, this "ability includes permanent spells (Artifacts, Creatures, Enchantments, and Planeswalkers), not just Instant and Sorcery spells." Against a mono-color deck, Iona offers a devastating blow
Stalking Stones is that card