Rule 10c. _Parts of a design differing in function should differ in appearance but be co-ordinated with the entire design._
[Illustration: SURFACE ENRICHMENT OF SMALL PRIMARY MASSES IN PRECIOUS METAL
ENRICHMENT OF FLAT PLANES OF PENDANTS, CHAINS, LOCKETS
In pendant design the surface enrichment generally carries the attention from the contour of the pendant to the stone, thus insuring unity at this point, while the contour lines often lead the attention from the pendant to the chain. The eye should move in unbroken dynamic movement from pendant to chain. The chain may have points of accent designed to vary the even distribution of the links. These accents are frequently composed of small stones with surface enrichment sympathetically designed in unity with pendant, chain, and stone. Figure 401 shows examples of this arrangement and similarly the need of a horizontal inceptive axis to harmonize with the length of the chain. These small accents are quite similar in design to bar pin motives.
Rule 10m. _Transparent and opaque stones or enamel should not be used in the same design._
For the designer's purposes we may consider two kinds of stones, the transparent and the opaque. These should not be mixed in one design. The most favorable stones are those forming contrasts of value or brilliancy with the metal as, for example, the amethyst, lapis lazuli, or New Zealand jade, with silver; or the dark topaz, or New Zealand jade, with gold. Lack of these contrasts gives dull, monotonous effects that fail to make the stone the point of concentration. Figure 467. These effects may be partially overcome by frosting, plating, or oxidizing the metal, thus forming stronger contrasts of value.
Plates 52 and 57 are representative of the steps, processes, and problems for school use.
(_b_) Locate the inceptive axis in this primary mass with its direction determined by the ultimate use or position of the primary mass and its general shape.
(_d_) Locate point of concentration in the zone of enrichment and in the inceptive axis.
(_f_) Design leading lines in sympathy with the contour and leading toward the point of concentration.
(_g_) Elaborate the leading lines in sympathy with the material, the type of enrichment, the contours, and the inceptive axis.