At the The Oasis of Marr speak to Mamat ( -1248, -215, -292 ) Copy/waypoint -1247.67, -215.01, -291.76 then Baniti ( -1232, -215, -299 ) Copy/waypoint -1231.66, -214.66, -299.34.
Travel to The Barren Sky and on The Whisperwind Isle at The Stonefall Breach collect dust from 12 Djinn Dust Wisps ( -529, -72, -353 ) Copy/waypoint -528.73, -71.99, -353.30. These will become agressive/attackable when you approach within 5 metres.
Return to The Sinking Sands and hail Baniti ( -1232, -215, -299 ) Copy/waypoint -1231.66, -214.66, -299.34 to give the pile of dust. At this point Baniti will turn your screen a monochrome green.
On the Orc Highway smash the glowing pile of rocks ( -501, -103, -139 ) Copy/waypoint -501.26, -102.67, -138.60 and enter The Fractured Cache.
Kill Cruor Mother ( -114, -71, -74 ) Copy/waypoint -113.84, -71.38, -73.56 and receive the text "The sudden sound of a stone cracking echoes through the Fractured Cache. Passage into the adjacent caves may be possible!".
Attack the cracked wall ( -69, -68, -95 ) Copy/waypoint -68.99, -68.39, -94.91 and enter the small cave.
Kill seven (7) Rujarkian Grunts and kill Overseer Ovlogg ( -89, -71, -197 ) Copy/waypoint -89.13, -70.85, -196.71. This will trigger the exposure of the next cracked wall ( -45, -73, -176 ) Copy/waypoint -45.22, -73.18, -176.24.
Kill The Ephemeral Guardian ( 3, -64, -186 ) Copy/waypoint 2.92, -64.31, -185.60 and collect the Ancient Crystal Arca ( 7, -65, -191 ) Copy/waypoint 7.09, -64.56, -190.94
Fast travel to the appropriate Quest giver of Faezoth in Qeynos Capitol District ( 696, -19, 223 ) Copy/waypoint 696.41, -19.42, 223.11 or Silrena in Freeport ( -117, -25, 207 ) Copy/waypoint -116.51, -24.97, 206.94. Or exit the cache ( 24, -40, -126 ) Copy/waypoint 24.17, -39.89, -126.23.