100 gm smalti from the standard and iridescent ranges is about 35 pieces. One kg of smalti from the standard and iridescent palettes covers approximately 750 sq cm, that is, an area 27cm x 27cm. This figure allows for 10% wastage. Another way to calculate it is 14 kgs per sq metre.
Please note that these are slightly transparent, which is hard to see in the photo.