You take the time spent casting the spell to transfer arcane runes onto the ruby, which must remain within 5 feet for the duration of the cast. After the spell is complete, you can enchant the ruby with one of the following effects; darkvision, detect magic, read all writing, or allow one to see into the ethereal plane. In order to benefit from this effect, you must hold the ruby up to your eye and peer through it, causing everything to be covered in a faint red tint. The effect can last a duration of 10 minutes, regaining any lost time every day at dawn. Once you enchant a ruby in this way, you may cast the spell on the same ruby to change the effect.