White jade specifically refers to nephrite (Hetian jade) which is primarily composed of tremolite, while jade formed mainly from other minerals cannot be called white jade simply because of its white color.
To identify Hetian white jade by appearance, there are three aspects to consider. The Hetian white jade exhibits a fine, dense structure resembling small cloud-like or mist-like patterns that form unique jade flowers, which are characteristic features exclusive to Hetian white jade; the luster of Hetian white jade is very smooth and warm, not the overly strong glassy kind. This means that the surface of Hetian white jade does not strongly reflect light, due to the extremely fine unevenness on its surface, similar to frosted glass, which can be seen with a 10-20 times magnifying glass. Sometimes, one may even see marks left by manual processing...