Alpaca fleece is a lustrous and silky natural fiber. Guard hairs are distinctly silver-tipped giving the cat a silvery sheen or lustrous appearance. The blue hue is a vivid, lustrous and luscious rich solid cobalt blue. After firing, this produces bright colors and a lustrous sheen. This is indicated by its tennis ball size and lustrous greenish yellow sheen. The free electrons also prevent transmission of visible light, making metals opaque, shiny and lustrous. Pure platinum is a lustrous, ductile, and malleable, silver-white metal. The branchlets are smooth, and lustrous, initially reddish, maturing to dark gray, and finally brown. Yttrium is a soft, silver-metallic, lustrous and highly crystalline transition metal in group 3. The Egyptian preference was towards the use of bright colors, lustrous stones and precious metals. Angora goats produce long, curling, lustrous locks of mohair. It gives a coat which is hard, lustrous and durable. Chiffon is smoother and more lustrous than the similar fabric, georgette. The Angora breed of goats produces long, curling, lustrous locks of mohair. It is a steely-grey, lustrous, hard and brittle transition metal.