Ezarri recommends epoxy grouts, which require less maintenance, last longer and suffer less deterioration
Best Grout for Glass Tile: How to Pick the Right Grout
Starlike Crystal EVO 700 Translucent Epoxy Grout - Blue Water Pool Mosaics
All About Epoxy Grout (Read This Before You Pick a Color!) — The Grit and Polish
Cleaning and Maintenance of the mosaic
Mosaic Tiles for Decoration Blog - Ezarri
All About Epoxy Grout (Read This Before You Pick a Color!) — The Grit and Polish
All About Epoxy Grout (Read This Before You Pick a Color!) — The Grit and Polish
Choosing The Best Tile Grout For Your Project - Ocean Mosaics
How to Grout Tile in 6 Simple DIY Steps
Tile Grout and Thinset Buying Guide