翡翠 Jade has been known and treasured for more than 7,000 years. But only in 1863 was it discovered that jade is actually not a single mineral. What was traditionally called jade is in fact two separate and distinct minerals: jadeite and nephrite.
Nephrite is the more common form of jade. Nephrite ranges in color from mid- to dark-green or grey-green, but it can also be white, yellowish or reddish. Nephrite is slightly softer than jadeite; nephrite is 6-6.5 on the Mohs scale, while jadeite is 6.5-7. They have quite different chemical compositions as well; nephrite is a calcium magnesium iron silicate while jadeite is a sodium aluminum silicate. The two minerals also have different densities. Jadeite has a density of 3.30-3.38 while nephrite is less dense at 2.90-3.03.
综合评分 -> 10
man their gems are pretty good, and the prices aren't to bad either, I like checking out hte gems on there website, beceause the pictures of the gems are taken pretty well, and you can see the table, and the facets.
I love gemselect and I have bought a fair amount from them. The only complaint I have is not being able to save gems. I have a lot of projects so i am in the market for a lot of different gems and it's so disappointing to have to delete them all just to purchase one or two that I have saved in my cart.