Practice identifying the initial letter as your learner matches letter cards to the rock names. Remember to focus on learning the sounds the initial letters make and don't focus too much on if they know the names of all the rocks.
Incorporate some movement into your letter practice with this sign language code. Practice the signs for the different letters with your learner. Then you can show them the code with your own hands before having them figure it out on paper.
This worksheet asks learners to cut out rocks with letters on them and glue them in alphabetical order. See if your learner can identify which letter is missing before they glue it down.