Omphacite jade is a special species of jade consisting mainly of omphacite. Ouyang Qiumei define it as a kind of single mineral jade composed of more than 90% omphacite, with special attributes characterized by blackness in the reflecting light, greenness in the transmitted light, and strong vitreous luster. In recent years, the high-quality omphacite jade has been much sought after by the market and collectors because of its delicate texture, strong vitreous luster, dark green to black color under the reflection light and bright green color under the transmitted light. This paper discusses the main structural characteristics of omphacite jade and its mineral particle size, morphology and fracture development that remarkably influences the transparence of omphacite jade.