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.
Cork oak section. Cork is a protective, waterproof layer of dead cells that have thick walls impregnated with suberin, a waxy material. Cork is found as the outer layer of stems and roots of older woody plants. The cork oak (Quercus suber) of southern Europe and North Africa produces a profuse amount of cork which is harvested commercially every 3 to 4 years.