A perverse fracture will snap a point in half but it will not look like a perfect "snap" break, if you know what I mean.  On a small scale, a perverse fracture is the thing that takes off a barb when you're trying to notch a point.  Especially with deep notches.  The "wave" of the fracture doesn't run parallel to the face to create a shell-like scar.  It turns almost perpendicular and "slices" through the workpiece.  There are pictures out there of artifacts with this type of fracture but it may take a while to find a good one...