This quest can be quite hard if your group is sub lvl47.
Reasonably hard 47-50 also, but doable without to much hardships.

Celebrian Diamond:

Lord Vyletongue, purple passage drops this. Straight forward encounter vs hunter:ish mob with stun/snare attack and ranged "crossbow".
Will come with two stealther mob adds.
Infront of lord vyletongue, there are two stealthermobs that can be pulled separetly or both.
they are at the ][ narrow part infront of the vyletongue. GTAOE attack pulling is a excellent way. This mob can be farmed for an excellent cloth belt and a bunch of great daggers etc.

Celebrian Rod:

Dropped by Noxxion in orange part.
Be advised, several guides on the web suggest reaching noxxion the purple way..
that is ill advise.
There is a passage where you will with 100% certainty get a double lasher and smaller lasher version pull. (ramp up).. hard even for a lvl50 grp with 2 mages. 80 yard(?)ae stun or smt..
Go to noxxion the orange way, take on slugs by one man taking aggro from all and kiting them while mages/warlocks/priests assist kills one at a time. no tanks should go head on with these.
When in room with the larva spewer, time when big larva has passed and gone away. then clear room of small larva. the tank if any can while mages/warlocks take car of the none elite larvas by AOE, rightclick the spewer to destroy it.
Clear a passage in large chamber to Noxxion through the non elites, be aware of teamembers HP after killing the small larvas. stacking poison attacks.
NOTE! killing noxxion will at current time of patch 1.2.3 2005-03-15, most likely crash your entire groups, game client.
if you are lucky one makes it and can reinvite and you can loot the rod.
The noxxion encounter, pretty straight forward really priests spread out real good, a X pattern is good, tank takes on noxxion pulls it in inside X. casters singel target nuke with fire/arcane/frost/shadow. a good idea if a mage is withing pbae range of noxxion. when noxxion dissapear mage starts to pbae down the none elite shards, while the other mage come in and help pbae or warlock ae.
when non elites are dead or a certain time has passed noxxion will repop. go back to singel targeting. or you will run out of mana.

Bringing diamond and rod to celebras.

You can push on and go through razorlash, a warriormob with dualwield fasthitting attacks.
keep the priests on their toes.
Avod going all the way down ramp in center room at waterfalls, masspull warning as mentioned in the beginning.
jump down on solo lasher, or the 3 snare flowers.

at Celebras ONE! kill him easy encounter with non elite adds. group member start the encounter, if more click it can help bug the encouter up. follow celebras to the stone. one at a time click the book he lays onfront of it.
If he buggs and keeps going back to stone. when some1 have clicked etc. wait 5+ minutes, and he will timeout and the quest will be "completeable".

The Celebrian Rod is found in the orange side of Mara and drops from Noxxian, a poison elemental 48 elite. The Celebrian Diamond drops from Lord Vyletongue in the purple side of Mara. Noxxion can hit fairly hard and spawns little adds during the fight. Vyletongue has two hidden demons that join the fight once it begins. When you've received both items, you need to defeat Celebras who is closer to the end of the purple side (near where you zone i if you have the scepter already). He spawns many adds but once you defeat him, speak to his ghost to complete the quest.

Sadly if you have entered the instance via the portal created by the scepter and your party wipes. You will have to ressurect at one of the orange or purple portals and come back to use the scepter.

she's located in the outer network of caves leading to maraudon. Head down, when you reach the split of orange and purple crystals, she's located in the orange cave area in a pool of water. The water shows up on the map. The orange pool of water is deeper in that's required for another maraudon quest.