Carat weight, or mass, is just one of many gemstone properties measured at GIA (box A). Measurements of physical dimensions and facet angles of polished gemstones, assessment of color and ...

ABSTRACT In southeast Vietnam, gem-quality anorthoclase is found as megacrysts in Cenozoic alkali basalt. The crystals are transparent to translucent with vitreous luster and can be near-colorless, ...

JAS, ‘The Select B2B Show,’ with the continued theme “Connect to Source,” will be held from 5th to 7th July 2024 at JECC Sitapura, in Jaipur. The Pink City has been long known as a treasure trove for ...

橄榄石生日石的保养与清洁 橄榄石 的 莫氏硬度 为 6.5 至 7，比许多宝石都要软，不适合佩戴，因此不建议镶嵌于日常佩戴的戒指中。有些酸性物质（甚至是长期接触酸性汗液）会损坏这种八月生日石。清洁橄榄石是一个非常精细的过程。千万不要使用蒸汽或超声波清洁装置，因为您的橄榄石生日石 ...

Diamond Origin Report Full 4Cs assessment with a plotted clarity diagram, geographic origin and GIA report number laser inscription. For loose, natural D-to-Z color diamonds only, weighing 0.15 carats ...

GIA 知识交流研讨会是一系列演讲和研讨会，与参与者共同探讨当今宝石学面临的各种最为紧迫的问题，包括宝石原产地、实验室培育宝石和实地宝石学的新发现。这些网络研讨会由GIA 博士、实地宝石学家、教育工作者和研究科学家主讲，他们的专业知识与经验会为您提供丰富的宝石知识。 交流会对 ...

Pantone Color Institute（彩通色彩研究所）将“活珊瑚橘”判定为彩通 2019 年度代表色，提醒我们珊瑚是动物世界的一员，有助于维持海洋生态系统的平衡。珊瑚是受保护的物种，根据美国法规，需向美国鱼类及野生动物管理局提出申报并 得到其许可才能进行捕捞。夏威夷发现的黑珊瑚是美国唯一可以 ...

Modern collisional tectonic events are generally initiated with subduction of oceanic crust beneath the continental crust and down into the mantle. Subduction of the oceanic crust has been linked to ...

ABSTRACT The published literature offers only a few records of direct measurement of the natural radioactivity in nephrite. The present study used high-purity germanium (HPGe) low-background gamma-ray ...

Figure 1. Pinctada maxima shells: gold-lipped (left) and silver-lipped (right). Their names are derived from the color of their nacreous shells. Photo by Nuttapol Kitdee. ABSTRACT Non-bead cultured ...

ABSTRACT Thirty-seven pearls originating from bivalves of the Tridacnidae family were analyzed to determine their gemological properties and to characterize the optical features of their distinctive ...

Figure 1. Age plot for all the diamond mines that have supplied enough diamonds on which to do age studies. This diagram summarizes all the known diamond growth events through time. Diamond mines ...