GLASS

Vitreous (non porous & frost proof in a wide range of colours, smooth on the surface and ridged on the back for better adhesion)
Iridised (reflective quality)
Marbled (contrasting & complimentary marbled colours)
Metalic (semi-transparent solid colour with gold/bronze veins)
Gold & Silver Leaf (famously used in Byzantine mosaics of Ravenna)
Millefiori (round handmade Murano, Italian feature tesserae of 'a thousand flowers' dating back to 15th century)
Sicis (Italian square tesserae with rounded corners)
Smalti (handmade Italian rectangular bricks of opaque glass used in Byzantine mosaics of Ravenna. Best left ungrouted due to its naturally occuring bubbled surface.)
Sea glass
Beads
Marbles

CERAMIC

Unglazed (most commonly from France & Portugal. Terracotta tesserae featured in some of the very early mosaics of Sumeria)
Glazed (eg wall tiles)

STONE

Marble (often sold in rods)
Pebbles
Chippings (used in Roman mosaics cut into cubes)
Slate
Granite
Semi-precious stones

CHINA

Broken crockery

SHELLS

Limpets
Mussels etc

MIRRORS

Tiles etc

BUTTONS

The list is endless, virtually any material can be used to make a mosaic!

Sue Kershaw
Mosaic Artist (UK based)
www.mosaicart.org.uk