Gemological and Mineralogical Studies of Greenish Blue Apatite in Madagascar

Madagascar is known as the ‘Island of Gemstones’ because it full gemstone resources. Apatite from widely popular its greenish blue Paraiba-like color. This study analyzes apatite through standard gemological characteristic methods, spectroscopic tests and chemical analyses (i.e., electron probe laser ablation inductively coupled plasma mass spectrometry). work explores diagenesis information recorded on by comparing them with other sources establishes origin apatite. The characteristics are follows: fluorapatite, excellent diaphaneity, greenish–blue color caused Ce Nd crystal structure distortion indicated tests. F/Cl ratio (16.47 to 21.89) suggests magmatic Cl loss during weathering processes forming source rocks, lg fO2 (−10.30 −10.35) reflects high oxidation degree magma.