According to the Gem Institute of America, jade is a term correctly used to describe two separate gems: jadeite and nephrite.

Jadeite comes in a wide variety of colors, including black, along with many shades of green, lavender, yellow, red-orange, gray and cream. The coloration can be streaked or mottled.

Nephrite comes in light and dark greens, brown, yellow, black, gray and white. Its colors tend to be less vibrant than jadeite and the stones are often streaked or mottled.

The finest jadeite is green, and the most sought-after green for jadeite is called imperial jade, which resembles an emerald. The dream color for nephrite is white. Jadeite ranges from opaque to semi-transparent, meaning you can hold text under the stone and it will be visible but blurry. Semi-transparent jadeite is considered the best. Both stones are extremely hard and durable. They are rarely faceted, instead polished to a pleasing smooth texture. China is the world’s primary polishing center and largest nephrite market in terms of sourcing, manufacturing and trading.

Hong Kong uses a classification system that includes “A” jade (jadeite that’s natural or only waxed); “B” jade (jadeite that’s been bleached with acid and infused with polymer resin); and “C” jade (a dyed material that likely is not jadeite or nephrite).