The mining texture on amethyst buds and crystals do not line up with the block

What I expected to happen was...:
When mining amethyst buds and crystals, the breaking texture was expected to line up with the hitboxes of the respective blocks.

What actually happened was...:
However, the default breaking texture was instead applied to the entire block in which it was located.

Steps to Reproduce:
1. Mine amethyst buds or crystals