Glittery rock is a term used to describe two types of rocks: MICA and geode. MICA is a type of mineral composed of thin, flat sheets that can be peeled apart. It has a glittery appearance due to its reflective properties. Geode is a type of rock that is hollow on the inside and filled with crystals. It also has a glittery appearance due to the presence of the crystals. Both MICA and geode are often used in jewelry and decorative items.