Also called Kumkum, Sindhooram
Vermilion powder applied along the parting of the hair.
Among the most significant of the sixteen, because it is applied by the groom during the ceremony itself — the sindoor daan — rather than worn beforehand. It marks married status and is one of the rites that constitutes the marriage.
Practised widely in North, East and Central India. Many South Indian traditions mark marriage through the thaali or mangalsutra instead, and do not use sindoor daily.
A practical health point worth knowing: some traditionally-made and cheap commercial sindoor has been found to contain lead or mercury compounds. Products from established brands, or food-grade and herbal alternatives, avoid this. It is worth checking, especially for something applied to the scalp daily.
Solah Shringar is a cultural tradition rather than a requirement — lists differ by region, and including or omitting any item is an ordinary family choice.