Is the indent deep or more surface (not very deep)?

Deep enough for your thumb to comfortably rub back and forth: after all, it is a worry stone. Relives stress.

Is this genuine gemstone?

PS. Regarding the answer about the Malachite: I don’t see that they even sell Malachite, so I believe the person who commented looked at the Kambaba Jasper and confused it for Malachite (both are green). Kambaba Jasper is a medium to dark green, with characteristic dark/black circles (or swirls) on it. The picture in the listing, as well as the customer picture in a negative review look spot-on for Kambaba Jasper. I believe if the customer rinsed off the stone and viewed it in bright light, they would see it is very similar to the listing picture (which I am sure was taken with very bright lighting). It is not unusual for crystals to have some dust/light dirt on them when received. The lapidary process (the cutting and polish of rough gemstones/crystals) is a very messy process, and the finished products are often stored together by type, so the bags have dust and lapidary residue floating around in them. Also, in response to the review complaining that these are “made in China”: China happens to be a country which is blessed with very rich and diversified crystal and mineral deposits, and a great deal of crystals and minerals are found there. China also has a labor force that is willing and able to do the hard work of not only mining these, but also the time consuming lapidary work required to created pretty shaped and polished stones. It takes me several hours, using a table saw and lapidary grinder to turn a “rock” into a shaped and properly polished crystal like a “worry stone” or a cabochon worthy of making into a pendant for a necklace. The “Made in China” sticker the reviewer is upset about is referring to the lapidary work involved (the source of the raw material may or may not be China, industry standards call for the “made in” label to reflect where the lapidary work was done, just like the jewelry industry’s “made in” labels reflect where the piece of jewelry was created, not the source of any gemstones in it). It is by no means is an indication that these stones are fake, or “created” in a factory. That’s just ignorance (and racism).