The compass setting — also referred to in trade literature as the compass-point setting — is a four-prong mounting in which the prongs are positioned at the cardinal points relative to the gemstone's table: north, south, east, and west. Unlike a claw arrangement in which prongs are placed at the diagonal corners of a stone, the compass setting orients each prong along the principal axes, producing a visually open, symmetrical framework that exposes the maximum surface area of the gem to incident light.

Geometry and Construction

In a standard four-prong setting, prongs may be placed either at the corners of a square or rectangular stone, or at the mid-points of each side. The compass setting specifically describes the latter orientation — prongs at the midpoints of the north, south, east, and west sides — though in practice the term is used interchangeably with "cardinal-point" placement in bench jewellery and trade catalogues. Each prong is typically formed from a fine wire or tapered claw of yellow gold, white gold, platinum, or palladium, bent over the girdle and polished to a rounded or pointed tip. The four-point geometry creates a cross-like silhouette when the piece is viewed from above, a characteristic that distinguishes the compass setting from the more common corner-prong arrangement.

Suitability by Cut

The compass setting is particularly well-suited to square and rectangular cuts — the princess cut, Asscher cut, emerald cut, and radiant cut among them — where the prongs correspond naturally to the midpoints of each straight edge. This placement secures the stone firmly without obscuring the corners, which are often the most visually defining feature of a step-cut or brilliant-cut square stone. For round brilliants, the compass orientation is equally viable and is sometimes preferred by designers seeking a more architectural, directional aesthetic than a standard four-prong basket provides.

Security and Durability Considerations

Because the prongs in a compass setting engage the girdle at the midpoints of each side rather than at the corners, the stone's corners remain exposed. For cuts with sharp corners — notably the princess cut — this exposure increases the risk of chipping if the piece sustains a lateral impact. Competent bench jewellers address this either by specifying a slightly heavier prong gauge, by adding protective corner beads, or by recommending the compass setting only for stones with bevelled or slightly rounded corners. For emerald-cut and Asscher-cut stones, whose corners are already cropped, the compass setting presents no additional vulnerability.

Aesthetic and Historical Context

The clean, cardinal geometry of the compass setting aligns naturally with the design vocabulary of the Art Deco period, during which rectilinear cuts and architecturally precise metalwork were dominant. Contemporary fine jewellery designers continue to employ the configuration for its ability to float a stone visually within the mount, lending solitaire rings and pendants a spare, modern character. The setting's cross-like prong arrangement also carries symbolic resonance in ecclesiastical and commemorative jewellery, though this association is incidental rather than inherent to the form.

In the Trade

The terms compass setting and compass-point setting are used interchangeably across North American and British trade literature, and both appear in bench jewellery instruction manuals and auction-house condition reports. The setting is specified by prong count, prong profile (round wire, flat, or tapered claw), metal alloy, and — where relevant — the presence of a gallery rail or open basket beneath the stone. When ordering a custom mount, specifying "four-prong compass" unambiguously communicates cardinal-point placement to the bench jeweller.