platinite
/ˈplatɪnʌɪt/ /ˈplat(ə)nʌɪt/noun
Metallurgy. Also with capital initial. An alloy of iron and nickel which has the same coefficient of expansion as platinum, used to make metal-to-glass contacts in light bulbs.
Origin
Mid 19th century (in an earlier sense). From platinum + -ite. With sense 1, compare -ite, and compare also earlier platinate.