Boron
B
atomic number
5
melting point
2076°C

1. When exposed to the blowpipe flame, many boron-bearing compounds (borates and many borosilicates) produce an intense yellowish-green (siskin-green in the literature) flame color; tourmaline (and a few other borosilicates) must first be powdered and then mixed with 1 part fluorite and 2 parts potassium bisulphate (a variation of Turner’s Flux) to produce the same results.

2. Dissolve the powdered mineral in dilute HCl and then wet a piece of turmeric paper with the solution, now dry the paper at 100º C (the temperature of boiling water); the paper will turn reddish-brown; if ammonia is poured on it, the paper will turn black.