The MX, IMX, BMS and BMZ series stereomicroscopes with illuminated bases can be equipped for viewing gems and other transparent objects with dark ground. The dissection plates of the illuminated base of each instrument is removed and replaced by a dark ground attachment. This is particularly effective with the BMS and BMZ series stereos at higher magnifications because of the rheostat controlled variable illumination systems of these models The MX and IMX series illuminated bases are already tapped for the addition of a gem clamp - illustrated. The BMS and BMZ dark ground accessories are equipped with an integral gem clamp. Both dark ground and gem clamp units are listed amongst the accessories of each series. MX Series Stereomicroscopes IMX Series Stereomicroscopes BMS Series Stereomicroscopes BMZ Series Stereomicroscopes