A lighting apparatus for emitting white light including a semiconductor light source emitting radiation with a peak emission between from about 250 nm to about 500 nm and a first phosphor having a peak emission between about 550 and 615 nm, wherein an overall emission spectrum of the lighting apparatus has a depression between about 550 and 615 nm, whereby the red-green color contrast is increased versus a reference illuminant.

Proposed is a phosphor capable of effectively inhibiting the occurrence of adverse influence of a sulfur-based gas while improving water resistance of the phosphor and effectively inhibiting the corrosion of a metallic member. A phosphor is proposed, which includes particles or a layer provided on the surface of a sulfur-containing phosphor, which contains sulfur in a host material, and containing a crystalline metal borate containing an IIA-Group element, boron, and oxygen.

A photoluminescent material including by weight a polymer matrix in a percentage comprised between 19.99% and 54.99%, a photoluminescent compound in a percentage comprised between 45% and 80%, porous silica in a percentage comprised between 0.01% and 1% and optionally a dye system and additives with a total percentage for the dye system and additives comprised between 0% and 15%. Also, an article made from or coated with this photoluminescent material.