Dense irregular connective tissue. Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in dense regular connective tissue. Substances formed[edit] This tissue comprises a large portion of the dermis. This type of tissue is also in the protective white layer of the eyeball and in the deeper skin layers.
Definition of VERMICULITE. : any of various micaceous minerals that are hydrous silicates resulting usually from expansion of the granules of mica at high temperatures to give a lightweight highly water-absorbent material.
Vermiculite can soak up 3 to 4 times its volume in water. It also attracts plant nutrients such as potassium, magnesium, calcium and phosphorus. Perlite is an amorphous volcanic rock that is rich in silicon. When mined for use as a potting medium, perlite is crushed and also heated to expand the particles.