Lot of Four Indigo Gabbro Obelisks

Indigo gabbro, also known as Merlinite, is a mineral conglomerate that occurs and is mined in Madagascar. The typical colors of these basalt rocks are a deep indigo-purple and black. It is frequently polished into decorative items and table tops.

The word "gabbro" refers to a large group of dark, coarse-grained, intrusive igneous rocks that are chemically equivalent to basalt. The rocks can contain a mixture of feldspar, chlorite, serpentine, muscovite, pyroxene, hercynite, and magnetite within in a charcoal-colored matrix.