Crystal candies encase other elements, similar to marmalade and licorice locks. However, they can be cleared by making matches underneath them (by moving the candy outside the crystal candy into it to create a match).
Candies and movable blockers can pass through them like jelly. Elements such as licorice locks and conveyor belts can be underneath them.
They can also be destroyed by special candies but they can't be destroyed by making regular matches next to them.
If an immovable blocker is underneath crystal candies in can only be destroyed with special candies.
This is one of the HTML5 exclusive blockers that resembles another blocker and is multilayered. This one seems to resemble Marmalade and Liquorice Locks, except they can have up to three layers and they can be cleared by swapping the candy inside with another candy to make a match inside them.
This blocker was released approximately one year (52 weeks exactly) after Candy Cane Fences, the first blocker exclusive to HTML5 version.
This is the first element to be required for candy orders in the level it debuts in.
Crystal candies make up the numbers 122, 123 and 124 in the tile map code (one-layered crystal candy, two-layered crystal candy and three-layered crystal candy, respectively).
This is the first blocker that can properly encase other encasing blockers. Candy cane fences and candy cane curls can surround other encasing blockers but it's possible to destroy the blocker they surround without breaking them completely.
This can lead to elements other than the candy frog being encased in two blockers at once, such as special candies in level 4600 and ingredients in level 4629.