Certified GKH Gardening Expert
This can be common with older Crassula. It is an indication that the plant requires a little more humidity than it is getting, but it is not going to kill the plant. You could mist the plant, but if you choose this method, then you may need to treat for powdery mildew on occasion.
A humidifier will likely be the better option.
Here is a collection of articles that will help you with the care of Jade plants: