Florida Stucco GM-BLUS 80 lb Bag Sky Blue Gem Pool Finish. Florida Stucco Gem Pool Finishes, the etch resistant marcite alternative, are a mill prepared marcite alternative blended with the highest quality selected colored quartz aggregates, white portland cement and proprietary additives to enhance strength, density, bonding and curing. A Gem Pool Finish will yield a hard, long lasting surface highly resistant to stains and spot etching prevalent with traditional pool plasters. Exposure of the aggregate produces a safe, slip resistant and non-abrasive surface that attains a compressive strength in excess of 3500 psi in 24 hours and exceeds 7000 psi in 28 days.