It's a confusing matter to say whether it's agate, jasper or chalcedony. To be easy to judge, agate and chalcedony is almost the same, translucent - while jasper is opaque. Between Agate and Chalcedony, actually the difference is when we look at Chalcedony mostly they don't have a pattern, "pure" translucent. On the other hand, Agate has a pattern, for example a banding pattern.
Nevertheles, all this kind of stones from Indonesia are interesting. Whether the soothing calm purple color of chalcedony, beautiful banding of agate or the picturesque form of jasper - all will intrigue you.