I have compiled a list of sources for the elements that are available to the amateur chemist. Molybdenum will be discussed here.
Molybdenum is a rather dull gray metal; it is one of the least reflective of the transition metals. It is also quite inert, high-melting, and corrosion resistant. However, it is vulnerable, to heat, like many other left side transition metals; it oxidizes to hexavalent molybdenum trioxide, which is an acidic metal oxide. Molybdenum sulfide, the most common molybdenum ore, is a slippery black substance similar to graphite. Molybdenum forms a wide range of colorful complexes in lower oxidation states such as the molybdenum blues. Molybdenum is insoluble in acids and bases. Its expansion rate is similar to that of silica glass.
In element form: Some high speed tool steels have about 0.25% molybdenum metal in them. The support wires for the filament in incandescent light bulbs are often pure molybdenum. The squares of foil used to seal the ends of halogen lamps are pure molybdenum.
In compound form: Moly grease contains molybdenum disulfide. Molybdates are used as animal feed supplements.
Here is my sample of molybdenum metal. It is the foil seal from a halogen lamp. It is encased in the quartz glass, with wires coming out each end.