I was finally able to check out all the locations that GW2 Wiki claims there are spots that have rich platinum ore nodes and verify them myself. I have decided to post my results here for the rest of the guild to take a look at.

Please feel free to ask anything at all that may help to enhance this for those who desire. With that if you also have locations to add please let me know and then I shall verify the locations myself.

This guide will tell of the various locations that have been claimed to have and that I have personally verified that contain rich platinum nodes.

V = Verified location that has a rich platinum node
NV = Not Verified or a location that is claimed to have a rich platinum node but I have not personally found it.

*DISCLAIMER* Not all servers have the same spawn areas at the same time. You may have to jump to another server to see if the node is there or not.

Bloodtide Coast

• NV - Remanda Saltmarsh - node located north of waypoint at Blood Bill's Base
• NV - Mentecki Pass - node located in cave
• V - Mole's Head - node located south of Glorious Drill Collective #4 POI [highlight=#dd9323]Champion Blood Ooze near node location[/highlight]
• V - Moriarity's Hold - node located south of heart

Fireheart Rise

• NV - Apostate Wastes (no further information given)
• V - Buloh Crossing - node located at waypoint [highlight=#dd9323]Champion Flame Legion near node[/highlight]
• NV - Fuller Cistern (no further information given)
• V - Havoc Steppes - node located at Atrox Castrum
• V - Onager Bivouac - node located northeast of waypoint
• V - Pig Iron Mine - node located at southeast part of the island
• V - Rebel's Seclusion - two nodes - each located east of the waypoint one of them on the base level and the second can be navigated by going through the ghost area
• NV - Switchback Canyons (no further information given)

Iron Marches

• V - Ebbing Heart Run - node located at Heartsond Falls
• NV - Echoslab Arches - node located northwest of vista
• V - Crystalwept Groves - node located north of skill challenge, along southeast edge edge of map
• V - Gladefall Run -node located next to vista
• V - Soldier Mesa - node located west of skill challenge
• NV - The Infestation - node located near Grundallion's Lair
• V - Victium Moors - node located  a decent ways south of The Blasted Hearth POI
• V - Sunken Halls of Clarent - node located at the bottom of the underwater entrance that borders Bloodfin Lake

Mount Maelstrom

• V - Criterion Canyon - two nodes the first is located at the top left of the Rata Pten temple and the other at the south left part of Rata Pten temple
• V - Murkvale - node located east of waypoint
• V - Whitland Flats - node located north of Observation Platform XKV
• V - Sunken Droknah - node located underwater west of Observation Platform XKV
• NV - Maelstrom's Bile - two nodes - not verified First is located in a small cave south of Maelstrom Waypoint, the second located on the rocks overhanging the lava northwest of Maelstrom's Core POI

Sparkfly Fen

• NV - Aleem's Penance - node located east of Ruined Vallah
• NV - Orvanic Shore - node located at bottom of waterfall
• V - Orvanic Shore - two nodes - first is located south of vista and second is located at Quinatl Deadgrounds
• V - Shimmerstone Cave - located in the room with the [highlight=#dd9323]Champion Cave Spider[/highlight]
• NV - Ocean's Gullet - node located deep underwater west of Mire Waypoint
• V - Karinn's Passge - node located east of Forvar's Waypoint in the cave
Timberline Falls [list]
• NV - Fisher's Eye Bridges - node located west of waypoint
• V - Gentle River - node located through an underwater cave located east of Thistlereed Grove
• NV - Gentle River - node located north of Gentle River Waypoint and slightly west of the vista
• V - Sector Zuhl - two nodes - both nodes are located within the jumping puzzle, the first is near the start, the second is in the room with the lava

This post is a work in progress.

I want to give a big thanks to Axyd for helping me out with how to make this post easy for our viewers and to all who help contribute.
I also would like to mention that much of this information can also be found here.