• journal_title：American Mineralogist
• Contributor：Hongen Gu ; Rui Zhu ; Weiwei Chen ; Dongliang Ma ; Yang Li ; Yutong Li
• Publisher：Mineralogical Society of America
• Date：2011-
• Format：text/html
• Language：en
• Identifier：10.2138/am.2011.3645
• journal_abbrev：American Mineralogist
• issn：0003-004X
• volume：96
• issue：8-9
• firstpage：1398
• section：Articles

Natural colorless calcite crystals are colored electrolytically by using a pointed cathode and a flat anode at various temperatures and voltages. Ca⁺ and CO₃⁻ color centers, Ca²⁺ vacancies, and CO₃²⁻ units are produced in colored crystals. Absorption spectral bands of the Ca⁺ and CO₃⁻ color centers, Ca²⁺ vacancies, and CO₃²⁻ units are reported for the colored crystals at room temperature. Pb²⁺ spectral bands are observed in absorption and fluorescence spectra of uncolored and colored crystals. The current-time curve for electrolytic coloration of natural calcite crystal and its interpretation with respect to the electrolytic coloration process are given. Creation and conversion of color centers are explained.