This is a Blue Ripple Jasper Teardrop Pendant. It is an excellent example of this form of Jasper. It comes with the silver-coated pewter bail, as well as the 18" necklace.
This stone is indeed ripple jasper, but it has been dyed in order to obtain the unusual coloration. These come in many variations and are indeed striking.
Jasper is a form of chalcedony quartz, and is opaque rather than clear or translucent like regular quartz or agate. It contains an abundance of impurities which give its interesting appearance. I understand that there are over 3,000 forms of Jasper.
(As always, if you don't like the choice of bail or necklace, just contact me and we can make changes.)