Are the stones in ring 1 and 2 are the same or different substances

stones in ring #1
density
5.92g/cm3
color
no color
hardness
8.5
melting point
2759 degrees celsius
not soluble in water

stones in ring #2
density
3.52g/cm3
no color
hardness
10.0
melting point
3547 degrees celsius
not soluble in water

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams