Gemological dichroscope

J.H. Steward, London
Dichroscope, lacquered brass with calcite (Iceland spar) and focusable ocular in mahogany case (10.1 x 6.9 x 3.4 cm). Tube (length 5.3 cm, diameter 1.6 cm) with adjustable specimen holder on the front.
Signed on the tube "MADE IN ENGLAND | J.H. STEWARD LTD. | LONDON", first half 20th century.

private collection