Lovely green shells. The colours are a little more vibrant than evident in these photos- I think. If you don't love green shells, the mother of pearl inside could be your focal.... don't be limited by your Tess-Array, play with your Tess-Array :)
Cut the elastic and utilise the lovely pieces in your next mosaic. Individual pieces are 27mm x 15mm long. There are about 60 shells in each circle Each shell has two tiny holes. 60-90 grams
You could even slice these with a dremel into smaller pieces. I would advocate a proper respirator mask, as cutting shells and inhaling dust has shown to be toxic. If you are using the shells as is, there is no issue. As mosaic artists you have to be informed of all the risk factors with all the products you use. Dust is dust in all its forms and can be dangerous when inhaled. Cement dust, glass dust, ceramic dust, shell dust... do not breathe them.......Wear a mask. ....as for the house dust type- I don't find that too toxic LOL (world's worst house cleaner)