I have compiled a list of sources for the elements that are available to the amateur chemist. Boron will be discussed here.
Boron is an element that exists in two forms. One is an extremely hard black crystalline substane. The other is a red amorphous powder. Both are slightly toxic. Boron is a semimetal that forms covalent compounds with the halogens. Boric acid is the only acid safe to put in one's eyes. Boranes can be used as fuels. Boron is difficult to extract and does not have many uses as an element.
In element form: Neodymium magnets have about 6% boron in them. This could be considered an alloy or a chemical compound, but it behaves more like a alloy than a chemical compound.
In compound form: Borax is made of sodium borate. Heat resistant glass is made of borosilicates. Boric acid is used in some insecticides and eye washes. Boron carbide is used in some bulletproof vests.
Here is my sample of boron. This brown boron powder, insoluble in hydrochloric acid, was made by dissolving a neodymium magnet in hydrochloric acid.