In PS, those who enter the Quasi-Elemental Plane of Minerals must save vs. petrification to avoid being fossilized (described as being "turned to stone, or possibly precious gems), once per day.
In MotP, those who enter the Quasi-Elemental Plane of Minerals must save vs. spell to avoid being fossilized once per turn (i.e. 144 times per day). If failed, there is an 80% chance of being turned to stone and a 20% chance of being turned to crystal or gemstone. Worse, in MotP, there is no "mineral" version of stone to flesh that the party wizard can cast. Only a wish will restore the character. Worse yet, in MotP, if the crystallized or fossilized victim is brought to the Prime Material Plane (or any plane with gravity) while still crystallized/fossilized, there is a 99% chance the fossilized/crystallized victim turns to dust!

In the Quasi-Elemental Plane of Mineral, I liked the idea of changing the numbers around so that there is an 80% chance of being turned to crystal or gemstones, and only a 20% chance of being petrified as stone. Makes the plane more challenging!
