Looking at the illustration, it seems just a tad different. The "over and under" patterns of the lines of diamonds are different. In the actual necklace, for instance, both of the ribbons on either side of the central one go under the line of rubies. In the illustration there is one over and one under, as there is in the central element while the necklace shows the line of diamonds over the ruby line. The illustration doesn't have pearls mounted along the line of rubies, either.

The illustration may not be accurate, of course, or there were simply two necklaces of a slightly different style.

D