Proline Decorative Concrete Systems Gem-Tex™ GT621W 5 gal Oceanside Winter Decorative Concrete Hardener. Proline GEM-TEX™ is a decorative concrete hardener that leaves a solid color surface enhanced with natural flakes of accent colors exposed through the use of DURA REVEAL™ deactivator. GEM-TEX™ is formulated with color coordinated additives that shine like crystals resulting in a natural, quartz-like finish that sparkles like a gem. The lightly exposed surface is slip resistant, ideal for around pools and/or patios. It is made with the finest quality pigments and premium cements. Durable silica sand is used in a tight fitting formula producing a high quality, abrasion resistant surface.