Create a Recuso Core sampler (table right next to quest giver works)
Look for 6 "grumblings" around the quarry area and take core samples.
The grumblings only spawn as you are approaching their location and will de-spawn in approximately 10 seconds.
They are located around the quarry walls as pulsing crystals on the ground.
Get very close to the crystal or the reading will fail. It is recommended that you stand on top of a crystal to ensure you are close enough.
Do not attempt to target the grumblings, this is a pointless waste of time. Just use the Recuso Core Sampler when in position.
It takes the tool a few seconds to give a reading.
The Grumblings have static spawn locations that do not move. There's an exact number of spawns that you need. Locations are:
( -34, 158, -21 ) Copy/waypoint -34, 158, -21
( -72, 179, -51 ) Copy/waypoint -72, 179, -51
( -38, 165, 106 ) Copy/waypoint -38, 165, 106
( 95, 156, 136 ) Copy/waypoint 95, 156, 136
( 208, 123, 97 ) Copy/waypoint 208, 123, 97
( 153, 108, 26 ) Copy/waypoint 153, 108, 26
On initial quest release the grumblings did not refresh after they de-spawned. At 16/12/2023 it is confirmed they do respawn after a reasonable time.
Keep an eye out for jiggly mushrooms in the same areas, as you will need to collect 5 of them.
Picking up the mushrooms requires 500 in Gathering. You can skill-up from attempts if your skill is too low. (450 with the Far Seas Trade Skill Prestige "Experienced Reaping" which adds 50 to all of your harvesting skills.)
These look like bright orange gum drops. (Depending on your display settings, these may appear as bright yellow)
Harvest tracking works. Shows up as Odd Looking Mushroom.