Summary
Doing any block updates with a placed amethyst buds/clusters on the side, will break it. The following action that are affected are:

• Powering other redstone components (pistons, dispensers, droppers).
• Composting plants with a composter.
• Using a furnace.
• Opening a barrel.
• Stepping on redstone ore (which turns lit).
• An oxidizing copper.

Original Description
Placing any size of Amethyst Bud on a Redstone Lamp and then powering the lamp will break the Buds/Clusters.
 
Steps To Reproduce:

1. Place any Amethyst Bud or Cluster on any side of a Redstone Lamp.
2. Power the Lamp.

Results: All Buds/Clusters break.

Expected Result: Nothing happens.