atomic number
melting point

1. Place a large mineral fragment (preferably one with smooth crystal faces) in a beaker containing dilute HCl, (be sure the sample is completely immersed in the acid), now add a few shavings of metallic zinc to the solution; the presence of the tin oxide (cassiterite) is confirmed if the submerged mineral fragment begins to take on a dull gray coating.

2. Mix a small amount of powdered mineral sample with a bit of powdered charcoal and some sodium carbonate flux, place some of the mixture on a charcoal block and subject it to the blowpipe flame; if the reducing portion of the flame is applied to the mixture, several small globules of white metallic tin will appear; eventually a white sublimate of SnO2 will form as heating continues.