Here's why:

* Streak refers to the color of a mineral's powder when rubbed against a streak plate (unglazed porcelain).

* Jasper is a variety of chalcedony, which is a microcrystalline form of quartz.

* Quartz is known for its hardness (7 on the Mohs scale) and is harder than a streak plate.

* Because jasper is harder than the streak plate, it will not leave a powder, and therefore, no streak is observed.

Instead of a streak test, the color, pattern, and texture are used to identify different types of jasper.