These are special harvest nodes with "deposit of Pi'ter Sahlt" above them. The locations were always up against large rocks, and always well out of the way of mobs. They also appear to have static locations and each rock yields 2 updates,so you only need 4 rocks.
Tinkerist Glazid has a grand experiment in mind, and has commissioned my help to gather the components he needs to complete it. First, he has asked that I mine a substance he called Pi'ter Sahlt, and return what I find to him. I can find deposits of the mineral in Camp Kromdek, which is found to the northeast of the Drogan Exile camp. I must take care, though, since if I were to strike the deposit improperly, it could explode.
I must mine deposits of Pi'ter Sahlt for Tinkerist Glazid.
Deposits of Pi'ter Sahlt collected
I have gathered enough of the Pi'ter Sahlt.
Return the Pi'ter Sahlt to Tinkerist Glazid
I have given Tinkerist Glazid the Pi'ter Sahlt.
I have collected the Pi'ter Sahlt for Tinkerist Glazid.
I have mined the Pi'ter Sahlt that Tinkerist Glazid requested.