The object has an elongated hexagonal outline that appears to have a piece broken off.  The interior is concave and shows a spherule-like object in the center.  Radiating from it are lines or grooves and the entire object has a uniform outline or lip.  This is a most unusual find and bears analysis.

The object first appears as a set of three frames of data, comprising L2, L5 and L7 filter images.  This is a crop from the L5 data, which is more easily seen than the L2 due to the dark nature of that frame. It is located to the middle left edge of the raw frame of data. The original image is here at the NASA/JPL web site.
This magnified view is construction from all three frames at equal weight, yielding a broad spectrum image that shows fairly good detail. I assembled the images into a false color view and then noticed some strange features which show up in the contrast enhanced images that follow.
This false color image uses L2 as red (although it is actually infrared) and leaves the color unbalanced.  You can just make out a faint margin around the upper edges and a radial segments that lead from the center to the edges.
Here I have magnified and contrast enhanced the image, yielding a very clear view of the radiating lines and the margin around the object. The horizontal line through the center of the object might be a noise artifact or an actual feature.  Without more image data it is difficult to decide. Now let's look at the markup identifying the features more clearly.

This is one of the more unusual findings that I have made, and it does seem to be of biological origin.  The shape is distinctive, the object is hexagonal and concave, there is a perfectly centered round bulge, and there are clear radial lines centering on it.  The lip is clear around the object, and it is a true mystery.  It may be related to the strange rind objects that I and others have located, which are detailed at this link:

http://xenotechresearch.com/marsrind.htm