NOVELTY - An abrasion-resistant decorative coating is produced on surface(s) of an electrically conductive substrate by ion-assisted plasma depositing of composite diamond-linked carbon decorative coating from precursor gases. The precursor gases are hydrocarbon, silane, organosilane, organosilazane and/or organo-oxysilicon compounds.    USE - For coating electrically conductive substrates e.g. sporting equipment such as shafts and heads of golf clubs (drivers, putter, wedge or irons) (claimed), brass hardware, brass fixtures, jewelry, medical instruments, dental instruments, writing instruments, musical instruments, eyeglass frames, cigar lighters, cigarette lighters, automobile ornaments, cycling equipment, fishing equipment or hunting equipment.    ADVANTAGE - The composite diamond-like carbon decorative coatings provide high durability for protecting the substrate from scratches and abrasion; resistance to corrosion by environmental conditions such as humidity, salt or acid rain; and high adhesion to the substrate such that cracking or flaking does not occur when the substrate is subjected to flexure or high impact conditions. They can be made with high luster or low luster if desired. They can be applied at low substrate temperature. They are amorphous and without the drawbacks of grain boundaries found in polycrystalline materials. They have the ability to hide fingerprints, when applied over substrates with a variety of surface finishes.    DETAILED DESCRIPTION - Production of an abrasion-resistant composite diamond-linked carbon decorative coating on surface(s) of an electrically conductive substrate involves ion-assisted plasma depositing from carbon (C)-containing and silicon (Si)-containing precursor gases. The coating comprises layer(s) of Si-doped diamond-like carbon (DLC) containing C, H and Si. The precursor gases are hydrocarbon, silane, organosilane, organosilazane and/or organo-oxysilicon compounds. A substrate bias at -100 to -1000 V is used. A product is recovered coated with the decorative coating having a nanoindentation hardness of 5-35 GPa and a thickness of 1-25 mm.    DESCRIPTION OF DRAWING(S) - The figure is a diagrammatic view of a capacitively-coupled RF plasma deposition apparatus.    Vacuum chamber (10)    Grounded electrode (12)    Substrate (13)    Powered electrode (20)