Quartz crystals with blue needles of Dumortierite inside. The locality, is western Bahia, near Vaca Morta Quarry, a remote and hard to reach area near the border with Tocantins state. - Photo: Jeff ScovilQuartz with Dumortierite inclusions
Natural Blue Obsidian (raw) Obsidian is a very special stone. It is not a true mineral. It is actually a volcanic glass that forms when molten lava cools too rapidly to crystallize. It consists mostly of Silicon Dioxide.