Soda Lime Glass, also known as soda lime silicate glass, is one of several formulations of glass which is manufactured in a shape of a sphere. There is not one standard formula for soda lime glass. In general, soda lime glass spheres contain about 75mol% of silica (SiO₂), 14%mol of sodium carbonate (Na₂O), 10mol% of calcium carbonate (CaO) and small percentage of other additives. It is the most common type of solid glass microspheres available, offered in a wide selection of sizes and grades (precision, classified, bulk and spacer grades).

Specific physical properties vary by product and lot number. The numbers below are general for soda lime glass and to be used for reference only:

• True Particle Density: ~2.5g/cc
• Index of Refraction: ~1.5
• Annealing Temperature: ~500C
• Softening Temperature: ~650C
• Thermal Expansion: ~80x10^-7/C
• Chemical Resistance: may be attacked by acids