How Rare are the Eidolon Gems : r/Warframe Reddit
That's 4 gems per run and it might take you 15 to 20 minutes or less which is much better than running mining runs. Especially since its a guaranteed outcome. The arcanes also needs Cetus Wisps. Lots of them. Just dont spend your rep on them as they are easy to find outside Cetus. Less random than Eidolon gems.