Reflex light reflectors and glass bead elements thereof

Claim 1

A GLASS BEAD THAT IS A TRANSPARENT TWO-ELEMENT SPHERE-LENS HAVING A DIAMETER NOT EXCEEDING 10 MILS AND ADAPTED FOR USE IN REFLEX LIGHT REFLECTORS OF THE CHARACTER DESCRIBED, FORMED OF A GLASS SPHERE INITIALLY HAVING A REFRACTIVE INDEX EXCEEDING 2.0 AND COMPOSED LARGELY OF LEAD AND BISMUTH OXIDES WITH THE BISMUTH OXIDE IN THE PROPORTION OF 20 TO 45% AND ALSO INCLUDING A SMALL PROPORTION OF AT LEAST ONE OXIDE OF THE GROUP CONSISTING OF PHOSPHOROUS PENTOXIDE, ARSENIC OXIDE, ANTIMONY OXIDE, TUNGSTEN OXIDE AND VANADIUM OXIDE, THE OUTER PORTION OF THE SPHERE HAVING BEEN LEACHED TO SELECTIVELY EXTRACT LEAD OXIDE AND LEAVE A SUBMICROSCOPICALLY POROUS SOLID SURFACE LAYER CONSISTING MAINLY OF BISMUTH OXIDE WHICH PROVIDES AN INTEGRAL CONCENTRIC LAYER THAT IS OPTICALLY HOMOGENOUS AND HAS A SUBSTANTIAL THICKNESS THAT IS A MINOR BUT PLURAL-PERCENT FRACTION OF THE DIAMETER OF THE RESIDUAL UNLEACHED GLASS CORE, THE CORE AND THE LAYER BOTH SERVING AS TRASPARENT SPHERICAL LENS ELEMENT OF THE COMPOSITE SPHERE-LENS.