個人積分：3分
文章編號：64961316
Natural citrine is very rare. Large quantities of amethyst, usually of lesser quality, are heated to turn it yellow or orange and sold as "citrine." Because the color is now caused by finely distributed iron minerals (mostly hematite and goethite), heated amethyst is not citrine in the strict sense, and also shows no dichroism in polarized light.
Thin coatings of iron oxides on colourless quartz, as well as inclusions of yellow iron oxides ("limonite"), may simulate citrine.
個人積分：128分
文章編號：64968050
個人積分：2分
文章編號：64970623
個人積分：10820分
文章編號：65011127
個人積分：247分
文章編號：65015434
個人積分：2分
文章編號：65027188
個人積分：315分
文章編號：67169349
個人積分：128分
文章編號：67172923
個人積分：35分
文章編號：67357642
個人積分：2分
文章編號：67400882
