Here's why:

* Density: Shale's density varies depending on the specific composition, but it typically falls within the range of 2.4 to 2.8 grams per cubic centimeter (g/cm³). This makes it heavier than common rocks like sandstone (2.2 g/cm³) but lighter than granite (2.7 g/cm³).

* Weight: A typical piece of shale would feel heavier than a similar-sized piece of sandstone but lighter than a similar-sized piece of granite.

However, keep in mind that the actual weight of a shale rock depends on its size and shape, which can significantly vary.