The origin of the name »Dumar« is unknown. Whether the name has anything to do with the Spanish. Mar = sea is speculative. As origin "China" is indicated.
Like many other newly discovered rocks, »Dumar« was initially called "Jasper" or "Lotusjasper". But the rock has nothing to do with the original jasper. Mineralogical investigations have shown that it's a very complex skarn rock. Skarns are metamorphic rocks formed by metasomatosis from limestone or dolomite rocks.
The Dumar-Skarn consists of a silicified matrix with very fine-grained tremolite, partially intergrown with dolomite and calcite. Additionally radial grown augite and aegirin-augite occur in larger crystals. In the lighter areas they are intergrown with albite feldspar. In between violet domains of fluorite occur, which forms in some regions idiomorphic crystals.