You discovered that those rocks are alive. But no other information about them are available.
You should probably find a way to keep yourself from forgetting words used for spells.
And then 1 simple word is what you need for magic. Saying 'open sesame' will do nothing as there is no sesame to open.
[The rocks start snoring. Yup, those things are alive and asleep]
(So 'speak' makes normally mute creatures capable of noise.)
[The book is in perfect condition, nothing except those few words have ever been written in the book]
The spellbook will automatically update with every new spell.
[There is no reason for silencing anything]
[The boulders explode in a fury of dirt and rock, when the dust settles you see a sleepy, cranky young rock troll. It takes a second before roaring and turning hate filled eyes on you.]