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.
The Cork-tree is resistant to drought and insects, and it can thrive in a variety of soils. It is hardy to zone 4 and it is easy to maintain, sometimes to the point of being invasive. One drawback is that the drupes fall and scatter, which may be undesirable on a formal lawn.