| The difference was so marked as to be easily seen without the dichroscope. |
| The stone was therefore inspected with the dichroscope and found to possess no dichroism. |
| The use of a dichroscope would have saved them that error, for the stone is singly refracting. |
| It polarises light, and when viewed with the dichroscope shows a remarkable variety of twin colours. |
| The student should, if possible, obtain the use of a dichroscope and practice with it on all sorts of stones. |
| The emerald is dichroic, giving in the dichroscope a bluish-green and a yellowish-green image. |
