Celtic Heroes

Favour of Cerridwen ability quest (in front of cave near graygorg, south of the leystone) - the quest specifically calls for "stones of night, stars and moon". Does anyone know the required items?
I'm thinking:

Night - Jet
Moon - Moonstone
Star(s) - ??? (diamond?) (peridot?)

,Anyone know?

Pretty sure, but I haven't tried it yet, diamond. I came up with this answer from twinkle twinkle little star lol