The name Luna (moon) Agate does not only come from the white, spherical eyes on purple chalcedony. The Russian satellite Sputnik 1 was launched when that agate locality was discovered. The lavender to purple colour is caused by manganese compounds that are mined close to La Mojina near Terrenates, the locality for that agate.
Luna Agates are known from different locations in Mexico, the best colour comes from the above mentioned La Mojina. Large nodular agates were found, all the material came from the surface.
Luna Agates show spherolitic growth from knotty centres inside the agate. Normally spherolitic growth starts from the edge of the nodule to the centre.
Further informations are given from Brad L. Cross in his book “The Agates of Northern Mexico”, page 81 - 83.