This Specimen has been sold.
3.5" Polished, Free-Standing Pistachio Opal - Madagascar
This is a polished, free-standing green "pistachio" opal specimen that comes from the Antananarivo Province of Madagascar. The polish of the specimen really amplifies the stunning green and orange hues that this mineral displays. The base has been cut flat for aesthetic presentation.
Green opal is an amorphous variety of quartz, with the chemical composition of SiO2 · nH2O. This hydrated silicate mineraloid has the associated chemical composition and lack of crystal structure that terms this mineral conglomerate as an opal.
During formation, microscopic holes form within the silica, forming secondary silica lamellae-like strings throughout, giving the rock its inner web-like appearance.
During formation, microscopic holes form within the silica, forming secondary silica lamellae-like strings throughout, giving the rock its inner web-like appearance.
SPECIES
Common Opal
LOCATION
Antananarivo Province, Madagascar
SIZE
3.5 x 2.6"
CATEGORY
SUB CATEGORY
ITEM
#211480