Low-priced stock that sells at less than $1.00 per share. Often highly-speculative and volatile, such as start-up mining companies. While, in general, penny stock are considered high-risk securities, some penny stock mature into less-speculative investments. All penny stock are traded over-the-counter.
In its natural form, cork is also a very good fire retardant, although cork dust is actually extremely flammable (because here the cell structure has been broken down). Impermeable: Cork has a magic chemical in its cell membrane that makes it completely impermeable to liquids and gases.
Because of its honeycomb-like structure, cork consists largely of empty space; its density (weight per unit volume) is one-fourth that of water. Unlike a honeycomb, however, cork consists of irregularly shaped and spaced cells having an average of 14 sides.