Which of the following asbestos types is NOT part of the serpentine group?

The asbestos type that is not part of the serpentine group is amosite. Amosite is classified as part of the amphibole group of asbestos fibers, which is characterized by different properties and structural formations compared to the serpentine group.

Chrysotile, known as white asbestos, is the only type that falls under the serpentine classification. It is characterized by its curly fibers, which make it more flexible, in contrast to the straight, needle-like fibers of the amphibole types, including amosite and crocidolite. Crocidolite, also known as blue asbestos, is another member of the amphibole group, which exhibits similar risk factors but differs in fiber structure and appearance.

Vermiculite is a mineral that can contain asbestos, but it is not a type of asbestos itself; rather, it's a phyllosilicate mineral. This distinction further highlights why amosite, being an amphibole, does not belong to the serpentine group, making it the correct answer in this context.