Scandium turnings ignite in air with a brilliant yellow flame to form scandium oxide. The properties of scandium compounds are intermediate between those of aluminium and yttrium. For example, scandium and yttrium are both soft metals. Strontium, barium and the elements from scandium to zinc are relatively depleted. Even more recently manufacturers have started using materials such as carbon fiber, titanium, or scandium. These alloys contain between 0.1% and 0.5% of scandium. Particularly promising is the strengthening of aluminium alloys with as little as 0.5% scandium. Sodium iodide and scandium iodide are commonly in use. The isotopes of scandium range from Sc to Sc. ScF can be produced by reacting scandium and fluorine. In all four halides, the scandium is 6-coordinated. Thortveitite can contain up to 45% of scandium in the form of scandium oxide. Compounds that feature scandium in oxidation states other than +3 are rare but well characterized. The first pound of 99% pure scandium metal was produced in 1960. He named the element scandium, from the Latin "Scandia" meaning "Scandinavia".