The adamas of Ancient peoples is proved to be the precious diamond. An ancient and uconventional diamond occurrence, the mines of Philippi in Macedonia (northern Greece), is geologically explained here. The most probable source is believed to be flat subduction-related (shoshonitic) lamprophyres that originated at a depth of >110 km within the mantle in the diamond stability field. The thick lithospheric mantle beneath Greece supports the occurrence of diamondiferous lamprophyric rocks in this area. However, no lamprophyre outcrops have been found, except for a few lamprophyre dikes 14 km SE of Philippi. Another explanation for the occurrence would implicate detrital diamonds that have been preserved in the local greenschist facies rocks. The XRD analysis of Philippi paragneiss showed the existence of the mantle mineral magnesiowüstite, which is a possible diamond indicator. The Philippi occurrence deserves detailed investigation involving alluvial sampling and ground magnetic surveys to locate the diamond source.

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A sequential genetic diagram is proposed for lamprophyres adopting their definitions, classification, petrological and geochemical signatures from an elaborated literature survey. Based on the definition of individual lamprophyric types, the existence of “Lamprophyre clan” of rocks is supported as it was first proposed by Rock in 1991. A diagram has been created for this purpose. Characteristic examples from India and their approximate spatial distribution in the eastern Dharwar craton in particular, have also been presented.