The Complete Jade Guide

Both forms of jade are vulnerable to strong acids and heat
Assuming the colour is natural and untreated, both jades are safe for steaming and immersion in an ultrasonic cleaner
If it is not known whether the gem was treated, a soft bristle toothbrush or damp, non-abrasive cloth should be used for cleaning
Deep natural colour and the homogeneity of the colour plays a large role in the appreciation of jadeite jade. Deep green, translucent jadeite is revered, but apple green jades are also highly appreciated. Nephrite jades with strong natural colours as well as materials that are carved into symbols are meaningful to collectors.

Smoothness: Impregnation with wax, polymer or parafin which enter tiny fissures, small cracks or pits resulting in a more uniform appearance
Color: jadeites with stained surfaces are submerged in acids with the aim of bleaching the stains often used in combination with parafin impregnation
Color: jadeite is often dyed. Colours may fade over time, especially exposed to strong light sources. Sometimes in combination with polymer impregnation

Jadeite jade: white, green, yellow to reddish orange, brown, grey, black, light purple
Nephreite jade: light to dark green, yellow to brown, white, grey, black

Jadeite jade: opaque often with mottled colors
Nephreite jade: transparent to opaque, creamy, often with mottled colors

Since most jades are translucent to opaque they are cut in cabochons or used in carvings