Iranian agates and the Khur agate field.
The Khur agate and geode locality (55`17'45"E, 33`39'25"N) is approximately 25km southeast of the Khur city, between Tehran and Yazd.
The agate and geode nodules are found in an altered tuff layer with lower to middle Eocene in age.
This tuffaceous layer in some places altered to montmorillonite (bentonite) completely.
In this localities agates and geodes find as loose
nodules on the surface.
But I will try to include a scan of geographical and geological maps of the area for more informationsin my English paper.
The descriptions of photos will come as following, in the order of their numbers.

K1-General landscape of the khur agate field. Altered tuff layer with white
color, that hosts nodules, is located in downslope of the mounds and covered
by a brown andesite lava layer. "Great Kavir" with it's salt playas seen in
the back of the mounds.

K2-Loose nodules on the surface of the altered tuff outcrop.

K3,K4 & K5-Relation between nodules and hydrothermal conduits.

K6-Geode nodule, Hydrothermal conduits, celadonite crust(which is rare in
the Khur nodules).

K7-Blue agate

K8-Dendrite agate

K9-Flame agate

K10-Blue agate with thick carbonate crust

K1-General landscape of the khur agate field.

K2-Loose nodules on the surface of the altered tuff outcrop.

K3 -Relation between nodules and hydrothermal conduits.

K4-Relation between nodules and hydrothermal conduits.

K5-A geode nodule near a hydrothermal vein that filled with chalcedony

K6-Geode nodule, Hydrothermal conduits, celadonite crust(which is rare)

K7-Blue agate

K8-Dendrite agate

K9-Flame agate

K10-Blue agate with thick carbonate crust