Overview of Gemstone Resources in China

Abstract

Gemstones are minerals of gem qualities used for adornment and decoration with the attributes of beauty, durability and rarity. Traditionally, although China has been regarded as the most important source for nephrite, over the past decades, a large variety of gemstone resources have been newly discovered in China owing to continuous exploration works. The vast land with various geological and geochemical backgrounds is rich in gemstone resources with potential for new deposits discoveries. In pegmatites, gemstones are related to granitic magma events and mainly occur in pegmatitic cavities, such as tourmaline, aquamarine, spodumene, spessartine, moonstone, quartz, apatite, and topaz. The eruption of Tertiary basaltic magma provides gem-quality sapphire, spinel, olivine, garnet, and zircon. The supergene oxidation zones of some copper and iron deposits in Hubei and Anhui province host gem-quality turquoise and malachite. Moreover, the formation of the nephrite deposit in China is mostly related to the carbonatite and serpentinite rocks involved in the metamorphic-metasomatic processes. This paper comprehensively introduces the distribution of gemstones deposits, as well as the gemological and mineralogical characteristics of gemstones in China. Our present investigation provides insights into the gemstone potential of China for further exploitation.

Water Molecules in Channels of Natural Emeralds from Dayakou (China) and Colombia: Spectroscopic, Chemical and Crystal Structural Investigations

“…The content of Rb is generally below 40 ppm. Although the average Cs content of Dayakou samples is the highest ever reported among that of worldwide emeralds [36,38], the calculated Cs + atoms per formula unit (apfu) are negligible. The main alkali ions in channel are Na + (0.131-0.287 apfu) and Li + (0.022-0.051 apfu).…”

Anatomy of Garnet from the Nanminghe Skarn Iron Deposit, China: Implications for Ore Genesis

“…Garnet is a widely distributed mineral with the general chemical formula [8] X 3 [6] Y 2 [4] Z 3 [4] O 12 , where X, the eight-coordinated dodecahedral site, is usually Ca 2+ , Mn 2+ , Fe 2+ , and/or Mg 2+ ; Y, the six-coordinated octahedral site, is generally Al 3+ , Fe 3+ , Cr 3+ , and/or V 3+ ; and Z, the four-coordinated tetrahedral site, is commonly Si 4+ [1,2]. Isomorphic substitution is prevalent in garnet, and ion substitution may occur at X and Y positions, or even in the Z position.…”

“…Garnet is common in magmatic, hydrothermal, and metamorphic rocks [4,5]. Gem quality garnet deposits are widely distributed in China [6]. Skarn deposits represent a globally significant source of Cu, Fe, Pb, Zn, W, Ag, and Au, and skarn garnets could be formed by both contact metamorphism and hydrothermal alteration of carbonate-bearing rocks [7,8].…”

Genesis of Color Zonation and Chemical Composition of Penglai Sapphire in Hainan Province, China

“…Studies on the genesis of rare elements above provide unique ways to determine the geographic origin of corundum [8,9]. The Penglai deposit in Hainan Province is one of the most important sapphire mines in China [10,11]. It lies within a basalt-hosted corundum belt along the western Pacific continental margin (Figure 1a).…”