I love Lariat necklaces. You don't know what that is?
OK, I'll try to explain. A "lariat" is the leather sling that cowboys use to catch cattle ("Lasso" in german).
In a necklace, it means that instead of having a clasp in the back, it just loops around itself - in front. The traditional style is just a single strand of leather, pearls or chain with decorative dangles on both ends.
If it's short, it is tied in front with a knot, like this one:
If it's longer, it can be worn as above, or doubled with both ends going through the loop, like this: