Ok, here goes my ideas for these special artifacts from all over the world
Base yield: +3 culture +3 tourism
Additional effects:
Rosetta Stone (found in Egypt): +3 culture when exposed in a museum, +6 culture when exposed in a wonder with an artifact slot
Stele of the Vultures found in Mesopotamia: +4 culture when exposed in a wonder with art slots
Rongo rongo, found on the Eastern Island: +10 science when exposed in any wonder with writting slots
Crown of Gaya, found in Korea: +3 tourism when exposed on museum, +6 tourism when exposed on palace
The Koh-i-Noor diamond, found on India: +5 gold when exposed in a museum, +10 gold when exposed in palace
Sword of Goujian, found on Hubei, China: +25 xp to units built on this city when exposed in museum, +50 xp when exposed in palace
Antikythera mechanism found in the Greek coast: +4 science when exposed in a museum, +8 science when exposed at the national collegue
Wulfing cache, found in Missouri, USA: +4 happiness when exposed in a museum, +8 happiness when exposed in the national college
Coatlicue statue, discovered on the main plaza at Mexico City: +3 faith +3 culture and +3 happiness when exposed in the great temple or pantheon wonder
Shroud of Turin, discovery site unkown: +10 faith when exposed in a cathedral, great temple, or sixtine chappel
- All these bonuses doubles once you finish the Aestethic SP tree
- Digging unique artifacts in foreign civilizations that has also finished this tree will result into MAJOR diplomatic penalties
- Unique artifacts are not suceptible for swapping. Finders, keepers!
As you can see, the possible combos with certain wonders and SP makes for very interesting choices to be made
