Wikia

Nerubian Archaeology Fragments are found with the [Survey] sub-skill of Archaeology.

Source

Some of the best zones to find them are mostly in Northrend: Borean Tundra, Dragonblight, Zul'Drak, and Icecrown, but some can be found in the Eastern Plaguelands of the Eastern Kingdoms.

Name	Rarity	Cost	Keystones
[Ewer of Jormungar Blood]	Common	45	2
[Gruesome Heart Box]	Common	45	2
[Infested Ruby Ring]	Common	45	3
[Scepter of Nezar'Azret]	Common	45	2
[Six-Clawed Cornice]	Common	45	2
[Spidery Sundial]	Common	45	2
[Vizier's Scrawled Streamer]	Common	45	2
[Blessing of the Old God]	Rare	140	3
[Puzzle Box of Yogg-Saron]	Rare	140	3