Snow doesn't settle on Polished Diorite

In the Snowy Mountains biome, snow fails to settle on polished diorite blocks. This behavior is inconsistent with other blocks where snow accumulation occurs as expected.

Steps to Reproduce:

1. Place polished diorite blocks in the Snowy Mountains biome.
2. Wait for snowfall.
3. Observe that snow does not accumulate on the polished diorite blocks.