Gilded Blackstone

Gilded blackstone is a variant of blackstone that can drop itself or gold nuggets when mined.

Occurrence
Gilded blackstone can spawn in Bastion Remnants.

From block loot
Gilded blackstone has a chance to drop gold nuggets when mined with any pickaxe, but Silk Touch is required to always obtain gilded blackstone in its block form.

Breaking
Gilded Blackstone requires a pickaxe to be mined, in which case it drops itself or gold nuggets. When mined without a pickaxe, it drops nothing. If Gilded Blackstone is mined with a Silk Touch enchanted pickaxe, it always drops itself. If it's mined with a Fortune III enchanted pickaxe, it always drops gold nuggets.

Block loot
Gilded blackstone has a 10% chance to drop 2-5 gold nuggets when mined with any pickaxe. If it does not drop golden nuggets, it will drop itself as a block. Fortune I increases the chance for this drop to 14.29% ($1/7$), Fortune II increases it to 25%, and Fortune III guarantees the golden nugget drop. If mined with Silk Touch, it will always drop itself.

Trivia

 * Gilded Blackstone is similar to gravel as it has a chance to drop itself or another item. So it is a variable ore. The chances to get said item can be increased by mining it with a pickaxe enchanted with fortune.
 * Gilded Blackstone seems to combine the textures of unpolished Blackstone and the texture of Nether Gold Ore prior to its texture change.