Apparatus for precisely cutting and polishing gemstones, said apparatus comprising a precision divider, a supporting device arranged to be located at a work bench comprising a lap for attachment of grinding and polishing devices, wherein the precision divider is attached pivotal to the supporting device, arranged to be pivoted and fixed with its longitudinal axis at a desired angle with the supporting device, said precision divider further comprising a mandrel exhibiting a dopstick recess arranged to accommodate a dopstick (122; 500) carrying a gemstone, and means for rotating the precision mandrel about the longitudinal axis and locking the mandrel against rotation during grinding and polishing of the gemstone, wherein the precision divider comprises a housing accommodating the elongate mandrel having a first end in which the dopstick recess is formed, and a second end exhibiting a precision graduated disk and a precision dividing gear, said mandrel, precision dividing gear and graduated disc being lockable at a desired rotational position with regard to the longitudinal axis by a mandrel rotation locking device (119, 123), and wherein the supporting device comprises a frame device arranged to be attached to a work bench via a support column in an adjustable manner both in the horizontal plane and in the vertical direction, thus enabling positioning of the frame device and the precision divider at a desired elevation and desired horizontal orientation, said supporting device further including a vertical angle adjustment device comprising a precision divider vertical angle dial and an angle locking device (211, 212, 213, 214), arranged to lock the precision divider in the desired angle position, characterized in that said mandrel, precision dividing gear and graduated disc are arranged rotary in relation to the housing, and in that the supporting device further comprises a fine vertical angle adjustment means (201, 204, 217, 224) arranged to perform fine angle adjustment of the precision divider as a supplement to the vertical angle adjustment device. the precision divider comprises a housing accommodating the elongate mandrel having a first end in which the dopstick recess is formed, and a second end exhibiting a precision graduated disk and a precision dividing gear, said mandrel, precision dividing gear and graduated disc being lockable at a desired rotational position with regard to the longitudinal axis by a mandrel rotation locking device (119, 123), and wherein the supporting device comprises a frame device arranged to be attached to a work bench via a support column in an adjustable manner both in the horizontal plane and in the vertical direction, thus enabling positioning of the frame device and the precision divider at a desired elevation and desired horizontal orientation, said supporting device further including a vertical angle adjustment device comprising a precision divider vertical angle dial and an angle locking device (211, 212, 213, 214), arranged to lock the precision divider in the desired angle position, characterized in that said mandrel, precision dividing gear and graduated disc are arranged rotary in relation to the housing, and in that the supporting device further comprises a fine vertical angle adjustment means (201, 204, 217, 224) arranged to perform fine angle adjustment of the precision divider as a supplement to the vertical angle adjustment device.