摘要
金和铜、银同属化学元素周期表中的第一副族元素.它有质量数为183—201的同位素,但只有同位素197的金最稳定。纯金为金黄色,金的颜色随杂质的含量而改变,银与铂能使金的颜色变淡,铜能使颜色变深。胶体状的金根据其分散程度及微结构的不同而显出不同的颜色。金的延展性很好。
Because there often exist some elements such as silver and copper, the gold-bearing jewelry has different percentages. As the corresponding relationship between the density and purity of material the density of gold-bearing jewelry could be changed after adding silver and copper elements. Comparing with the chemical and electron-probe methods, the gold-bearing jewelry and their percentage can be identified and measured simply, economically and quickly by the density method without destroying themselves. As a base of calculation of percentage a new formula is deduced as follows: Au(%)=〔((2.1932K+2.5701-23.0284(K+1))(W-W_0/Wρ_(H_2O)water))/(K+1.3770)〕×100 In practice, volume of gold-bearing and silver jewelry are measured by the water-drainage method, and their weight are weighted by the analysis balance. Through measurement of the density and observation of colour the percentage of gold-bearing jewelry can be obtained based on the calculation formula. In the measurement of gold-plated and hollow jewelry the percentage can be accurately identified by the density method combining with the electron-probe method.
出处
《江苏地质》
1993年第2期124-126,共3页
Jiangsu Geology