454 TALC GENUS. ✓ Obfervations'. 1. It is the link which connects talc With afryno- life and tremolite. 2. I he blue colour does not occur in any other talcy follil; it is therefore charafteriftic of kyanite. , It was at firft arranged in the flint genus, along with the fpecies fchorl ; as foon, however, as Wer ner had an opportunity of examining if, he found that it was eflentially different from fchorl, and con- fhtuted a difhnft fpecies, which by its natural charac ters proved to be a fpecies of the talc genus. 4- Its name is derived from the blue colour which fo remarkably chara&erifes it. 5. Varieties which hjve a fine berlin blue colour and confiderable tranfparency, are cut and fold » s fapphire. 6. The very pale varieties are fold for tremolite, but the flight tinge of blue which always accompanies the paleft, is a mark which diflinguifhes it fiom tre- xnohte. In doubtful cafes the geognofiic character is of afliftance : tremolite occurs ufually in limedor.e; but kyanite in talc or mica flate. twelfth
