TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The shell layer (B) is a metal, preferably coinage metal, noble metal, transition metal or synthetic metal such as polyacetylene or polyanaline, a metal like material or a metal alloy. (B) comprises an innermost layer adjacent to (A) and at least one additional conducting layer. (A) is a dielectric material, preferably silicon dioxide, titanium dioxide, PMMA, polystyrene or dendrimer or a semiconducting material. (A) is an organic molecule or an organic supermolecular-structure. (A) is a mixture of non-conducting material. (A) is an optically absorbing material or a fluorescent material. (A) comprises an outermost non-conducting core layer bound to (A) and at least one additional non-conducting core layer. (I) comprises a conducting layer sandwiched between two non-conducting layers. The diameter of the particles varies by less than 100%. (B) coats at least 10% of (A) but less than 100% of (A), and is a component in a second order, nonlinear optical material. (B) completely surrounds (A) and is linked to (A) by a linker molecule. (I) is approximately spherical. (I) has a core that is 1 nm to 2 microns in diameter and comprises silicon dioxide and is encapsulated by a 40 nm thick gold layer linked to the core by a linker molecule. (I) has a wavelength absorbance maximum of 300 nm to 20 microns. (I) is a mixture of particles of 5 nm to 2 microns thick. EXAMPLE - Aminopropyltriethoxy silane was used to treat a dispersion of monodisperse silica spheres for 2 hours, followed by dilution and boiling for 4 hours. The supernatant liquid was decanted and the solid redispersed ultrasonically. The resulting derivatized core particles were mixed with ultra small gold particles (average diameter 1-2 nm, prepared from a mixture of tetrakis(hydroxymethyl)phosphonium chloride, chloroauric acid and hydrogen tetrachloroaurate (III) trihydrate) in an amount to theoretically cover the core particle surface 5-10 times. The resulting metal clusters were enlarged by deposition of gold using a variety of reductants.