Jade is a gemstone that has been valued and sought after for thousands of years. The term "jade" refers to both jadeite, the rarest form of jade, and nephrite, which jadeite shares most of the same physical and chemical characteristics. Jade stones come in a variety of colors, the most popular being a muted green. Jade is commonly used to make jewelry, healing stones and small statues and figurines. Being a highly-valued gem, imitation jade is often introduced onto the market. Careful examination and testing can help you to determine if a rock is real jade or if it is just a cheap fake.
Examine the color of the rock. Real jade varies in color from emerald green to violet, orange, yellow, dark red, gray or even black and always has a soft, muted color tone. Look for extreme discoloration on the stone, which may be a sign that it is fake and was dyed to look like jade.
Hold the stone up against the light to evaluate its transparency. Authentic jade should have a subtransparent to subtranslucent transparency comparable to honey. You will likely see natural vein-like streaks running through real jade. Fake jade is often contains air bubbles that formed during production.
Feel the jade stone to evaluate its luster. Real jade has a glassy, wax-like texture and should sometimes even feel greasy. The surface of the stone should feel smooth, even-textured and cool to the touch no matter what the current temperature is. Fake jade will feel warm and clammy when held.
Perform a scratch test on the stone if you already own it. Use a knife or scissors and attempt to scratch an inconspicuous area of the stone. If the stone scratches easily it most likely isn't jade. While authentic jade has a smooth texture and appears polished it is an extremely durable and tough rock. Jadeite usually ranks 6.5 to 7 on Mohs scale of mineral hardness while nephrite ranks between 6.0 and 6.5.