The blow-pipe or dry test for minerals is convenient to apply to small bits or splinters of a stone.

The mineral is either held by a pair of platina-pointed forceps, or powdered and placed on a metal plate or in a glass tube.

Before the blow-pipe, some minerals change color, but do not melt, while others retain their color, or swell up, or break into small particles, or melt into colorless or colored glasses.

The following is the scale of minerals used to test the different degrees of fusibility:

1. Gray Antimony. Fusible in coarse splinters in summit of candle flame without the blow-pipe.

2. Natrolite. Fusible in fine splinters in the summit of a candle flame without the blow-pipe.

3. Almandite. Does not fuse in candle flame; fuses easily before the blow-pipe in obtuse pieces.

4. Green Actinolite. Fusible before the blow-pipe in coarse splinters.

5. Orthoclase. Fusible before the blow-pipe in fine splinters.

6. Bronzite. Before the blow-pipe becomes rounded only on the sharp edges.