You can try to wax them. Every shell mosaic manufaturer after they polished the mosaic chips and stick in a sheet,they have one step is waxing. After waxing,the chips will become very shiny. After construction,there will be having some dirty thing on the surface.That's the reason that is dull. Hoping this is useful for you. And the right way for installing that kind of shell mosaic is following: Construction way of our mother of pearl mosaic and tiles. We can lay glue or adhesive (We suggest to use tiny granule glue or white grout) on the wall and then put the mosaic on the wall by hand until the gap is filled with glue or grout (the hand pressure should be well-proportioned). After 30 minutes (for tiny granule glue 20 minutes is okay), you can clean the surface of the mosaic by dry soft cloth. 3.Shell Panel Application & Installation Commonly use to the backing such as MDF, Marble, Ceramic, Calcium Silicate Board, Plasterboard, Acryl and Metal. Using AB adhesive or all-purpose adhesive, apply even coat of adhesive to the panel and wall, and waiting for 5 to 8 minutes, then press it carefully to the wall. Immediately wipe off excess adhesive with a soft wet cloth, and dry with a clean soft cloth afterwards. 4. Protection and Cleaning 1. Please wipe the surface with charpie to reduce the nick; 2. Please clean the surface with neutral detergent; 3. Please wax shell mosaic surface regular time; Please Attention 1.Do not irradiate the surface with 100W above light. 2. The detergent should be faintly acid,because the content of shell mosaic are CaCO3; 3.Would better use tham soft cloth clean the surface,and wax them regular time for keeping the shiny. Hoping giving you some help! Here is a link that might be useful: Solar Shell Decorative Material.,Ltd

@dostk did you ever resolve this? We had a white and gray honed marble mosaic installed and after grouting, the whole area looks completely different. The stone doesn't look anything like the uninstalled mosaic, now it has almost a dull/frosted glass (not shiny) look to it ... is the best way I can try to describe it. Basically it doesn't even read as marble to me anymore. As far as I know, our contractor's installer did not seal it before hand (it was still in the boxes and packing sleeves) and used a sanded grout. The option of sanded or unsanded was never mentioned to us and as newbies we didn't know to ask. Is there anything that can be done to bring the original look back or is this just expected and we should have done a mock up as someone mentioned before?

Guess what?! Shower curtain arrived from Etsy yesterday and it looks great! Colors are even better in person than online. Copper and brown colors tie in with the tile perfectly and it brings much needed gray, white, and blue. Love! It is a little long, but I can easily re-hem. The Pottery Barn Odin rug wasn’t so lucky. The colors are kind of turquoise-y and sea glass green. So next I’m shopping for a 3’ x 5’ rug with gray-blue in it. Speaking of shopping...also need to look for art for the bedroom wall. The replacement one arrived, also with dents to the frame. Hubby brought it in from the porch and said, “Wow, this box is mangled!”

If your goal is to lighten up the house, avoid adding dark things to the already dark rooms. Add lighting, remove heavy dark window coverings, and check outside to see if there are branches that have grown to block sunlight from the windows. Pruning at the right time of year for your area can let in much needed light again. Start by replacing the light fixtures to improve the overall "dark and brown" look. Remove the over-sink bar cabinets. Paint the walls. Staining the cabinets can't be done well without stripping them, sanding, filling, staining, sanding, and so on. Contact the cabinet company with photos of the damaged areas. Ask them what clear coat can be applied over the existing finish. Chances are good that a clear polyurethane over a bit of stain pen will fix up those worn areas easily.