empty_slot_amethyst_shard does not show in Smithing Table slot

When you put a Smithing Template in the first slot of the Smithing Table and a piece of armor in the second, you see in the third slot the silhouette of an ingot, dust, lapis, quartz, diamond, emerald, and then the loop restarts: ingot, dust, ...

The amethyst shard never appears, but the file exists: textures\item\empty_slot_amethyst_shard.png