What are the glowing rainbow lights?

They signify where an artifact may rest.
How do I get the artifact?

You examine a scrying stone near the rainbow light. When you do, three runes (Tree, Sword, Coin) will pulse a specific intensity (Dim, Soft, Bright, Brilliant) and color (White, Red, Blue, Green) and one of three things will happen, you find nothing, you get attacked by mobs, or you find an item. If you are really fast you can get 7 scrying attempt from one rainbow effect. It seems to start a timer when you start the first scry, and cuts you off after a set amount of time. So if you get the mob spawn, go ahead and start your next scry attempt while you are fighting it.
Ranking the colors

This part is a work in progress, judging by data we have so far I am going to attempt to rank the colors. (ex. white seem to give better rewards than green) Any data you an provide to expand this would be helpful.

* Red - Lowest
* Blue
* Green
* White - Higest

Where do I get scrying stones?

You buy scrying stones from an NPC vendor, who is also the artifact vendor (possibly the artifact collector). There is one vendor on the docks in Thundering Steppes, and another on the docks in Nektulos Forest. This vendor sells scrying stones and buys artifacts back for 100% value. He does not sell artifacts.
What happens when I use a scrying stone near a rainbow effect?

There are several outcomes:

1. Nothing - You find nothing of value. Basically you just wasted a scrying stone, kiss 10s goodbye, thanks for playing.
2. Spawn - You disturbed something... A disturbed corpse spawns and attacks you. It is either a skeleton, zombie or ghost mob, level 16-24 and may be normal or have a single up arrow. The mobs tend to have normal loot for the mob type.
3. Item - You found something.
1. Coin Purse - The coin purse comes in various sizes. You get Ancient silver coins or Ancient Gold coins. The larger the coin purse, the more coins you get. The silver coins are worth 10s at the artifact vendor. As an alternate choice you are offered scrying stones at a 1 to 1 rate. There is a rare find when you get Brilliant White for all three runes, the reward is a Gold coin worth 10g or 100 scrying stones. Also reported is Brilliant Green for all three runes gives a reward of 50 coins or 50 stones.
* 3 Brilliant Red ???
* 3 Brilliant Blue ???
* 3 Bright White - 50 An Ancient Silver Coin or 50 scrying stones (value 5g)
* 3 Brillliant Green - 50 silver coins or 50 scrying stones (value 5g)
* 3 Brilliant White - 1 Gold coin or 100 scrying stones (value 10g)
2. Artifact - You found a damaged artifact. As an alternate choice, you can choose to receive scrying stones at a rate of 1 stone for every 10s of the artifacts value. The following is a list of artifacts found so far:
* An intact ancient comb - (value 40s) (Brilliant Red, Brilliant Blue, Brilliant Green)
* A damaged ancient basket - (value 10sp)
* A damaged fetish - (value 10sp)
* A lightly damaged ancient medallion - (value 30sp)
* A damaged ancient vest - (value 20sp)
* A perfectly preserved ancient lobster - (value 1g)
* Well preserved Clown shoe - (value ?)
* A damaged Urn - (value 10s)
3. Equipment - You found an actual equipable item with stats. These items do not sell back to the artifact vendor, but will sell to a regular vendor. The following are items found so far:
* Ruined Ancient Bangle 2 sta 3 agi 3 str 12 health 16 power 34 ac 80 cold 60 divine 40 mental usage skill 125 mastery 150
* Ancient Ruined Ring 2 sta 3 agi 3 str 12 health 16 power 32 ac at level 32 60 mental 60 disease 60 heat
* Ancient Chainmail Shoulderplates 188AC at level 35 5 sta 5 wis 15 health 13 power 134 cold 168 heat
* Ancient Hardened Gauntlets 7 agi 7 wis 17 health 27 power 242 disease 339 heat ac 208 at 24
* Rusted Ancient Boots 4 sta 2 agi 5 health 6 power 40 magic 80 mental AC 96 heavy armor skill 100 mastery 125
* Ancient Hardened Helm 5 int 9 wis 34 health 9 power 290 divine 290 mental AC 208 at 45 Heavy Armor skill 200 mastery 225 (value 4g96s) (Brilliant Blue, Brilliant White, Brilliant Blue)
* Frayed ancient sleeves: 14 health 14 power req 150 mastery 175
4. Books - You found a book. It is unclear what the ultimate purpose of these are at this time. What they do when you examine them is give you a timed mission to kill X number of mobs in X minutes. There is a set of books for each archetype. When you find this you will get to choose which archetype's book you will take, or as an alternate prize, you can choose scrying stones at a rate of 1 stone per 10s of the books value (Neophyte and apprentice books sell for 10s, Initiate books 20s, Accomplished books 30s). The books found so far are:

Book Types:
* Marshall for Fighters
* Archanist for mages
* Diviner for Priest
* Outrider for Scout

Book Titles:
* an initiate xxx's lesser training tome(kill 5 centuar in 5 minutes)
* an initiate xxx's standard training tome(kill 10 centuar in 5 minutes)
* an initiate xxx's greater training tome(kill 20 centuar in 5 minutes)
* an apprentice xxx's lesser training tome (kill 5 undead in 5 minutes)
* an apprentice xxx's standard training tome (kill 10 undead in 5 minutes)
* an apprentice xxx's greater training tome (kill 10 undead in 5 minutes)
* a neophte xxx's lesser training tome(kill 5 animal type in 5 minutes)
* a neophte xxx's standard training tome(kill 10 animal type in 5 minutes)
* a neophte xxx's greater training tome(kill 20 animal type in 5 minutes)
* an accomplished xxx's lesser training tome(kill 5 bixie type in 5 minutes)
* an accomplished xxx's standard training tome(kill 10 bixie type in 5 minutes)
* an accomplished xxx's greater training tome(kill 20 bixie type in 5 minutes)
* an experienced xxx's lesser training tome(kill 5 lizardmen type in 5 minutes)
* an experienced xxx's standard training tome(kill 10 lizardmen type in 5 minutes)
* an experienced xxx's greater training tome(kill 20 lizardmen type in 5 minutes)
* an master xxx's lesser training tome(kill 5 Thought Feeders type in 5 minutes)
* an master xxx's standard training tome(kill 10 Thought Feeders type in 5 minutes)
* an master xxx's greater training tome(kill 20 Thought Feeders type in 5 minutes)

Where do I find these rainbow effects?

Rainbow effects seem to appear only in certain zones and generally in the same areas. It is theorized that the spawn locations are on the same table as resource nodes. They spawn and remain in place for a certain time frame then disappear. You can get as many as 7 scrying attempts from one rainbow effect before receiving the message that this location is not active. Each person can get the same number of attempts, the effect does not diminish or despawn when someone scrys it. Some of the confirmed locations for rainbow effects are:

* Enchanted Lands
o Fairy island
o Halfling lookout post
o Goblin Ward Statue (The big head)
o In the farm fields near Foomby
o On hill overlooking Chompers pond
* Everfrost
o Island just to the left of the bell
* Feerrott
o Near Murdunk Falls
* Nektulous Forest
o Citadel of Gul'Thex
o Funeral Pyre
o Bone Lake
o Blackwater Pond
o Behemoth Pond
o Near Fireguard
o Camp Leeot
* Rivervale
o Scarecrow area
* Thundering Steppes
o Entrance to Ruins of Varsoon
o Sabertooth Den
o Graveyard just south of Sabertooth Den
o Crater Pond (near Goliaths, verify name please)
o Gnoll Cave (zone to Antonica)
o Grave Pool near Cove of Decay
o South Bandit camp
o Qeynos Tower 3
* Zek, the Orcish Wastes
o Spirit Lake
o The Pit mine
o Next to the Grenn Hood Trap Master
o Top of Deathfist Lookout (Titan's Tower)
o Near Druid Rings
o Around the Orc Camp where Tusk is
o In the nook containing the shattered mage spires

I think I'm in something of a "down" mood on EQ2 right now. Maybe if they manage to do an expansion that doesn't involve yet another bunch of disconnected floating islands, I might get fired up again...