Ivory

In the European jewellery context ivory was an important material until well into the 19th century, particularly for memento mori carvings (see Memento mori), for miniature portraits on pendants and for light accents in mourning jewellery. Today its use is strictly regulated by the international convention on the protection of species, CITES (1973); the market is shifting to historical pieces (antiques) and to alternative materials (mammoth ivory from Arctic finds, tagua nut). In the modern memorial jewellery sector ivory plays practically no role any more - the legal situation and the ethical assessment argue clearly against its use.

Material and properties

Ivory is dentine - the principal substance of mammalian teeth. In the narrower sense the term means:

• Elephant ivory - from African and Asian elephants; historically the most important material
• Mammoth ivory - from subfossil tusks from the Arctic permafrost; 10,000–50,000 years old, CITES-free
• Walrus ivory - smaller canine teeth, traditionally used in the far north
• Hippopotamus ivory - canine teeth, harder than elephant ivory, less grainy

Properties:

• Hardness: about 2.5–3.5 on the Mohs scale - workable with fine tools
• Density: 1.7–2.0 g/cm³ - heavier than water
• Colour: creamy white to pale yellow, darkening over time to honey tones
• Grain: characteristic patterns of Schreger lines in cross-section
• Sensitivity: hygroscopic (reacts to moisture), can crack in air that is too dry

History in mourning jewellery

Antiquity to the Middle Ages. Ivory pendants have been known since antiquity; medieval reliquaries (see Reliquary Pendant) and pilgrim badges were in part made of ivory. In the 12th and 13th centuries large workshops for religious ivory carvings emerge in Paris - Madonnas, crosses, devotional pendants.

Renaissance and Baroque (see Baroque (c. 1600–1750)). The peak period of memento mori carving in ivory. South German and Netherlandish workshops (above all Augsburg, Nuremberg, Antwerp) produce the finest skull pendants, small coffin models with a sliding lid and full-figure skeleton figures - all in ivory, often combined with gold mounts and gemstones.

A particular speciality: head-and-skull pendants - one hemisphere shows a living face, the other hemisphere a skull; the piece can be turned over when swung and makes the memento mori message vivid ("What I am, you were; what I shall become, you shall be").

Georgian and sentimental (see The Georgian Era (1714–1837), Sentimental Jewellery). Ivory becomes the standard picture support for miniature portraits on mourning and keepsake pendants. A small ivory plate (about 3 × 4 cm) is painted with the portrait by the miniaturist in fine watercolours; the finished picture is inlaid into a hollow gold setting and closed with a rock-crystal window. On the back there is often a lock of hair under glass (see Hairwork).

Victorian (1837–1901, see The Victorian Era (1837–1901)). With the advent of photography the ivory miniature loses importance. In mourning jewellery ivory becomes an accent material - small ivory reliefs on black enamel pendants, carved little ivory heads as the central element in a brooch or pendant. This intensive use runs parallel to the dramatic reduction of the elephant population in Africa and India.

20th century. The first protective provisions arise in 1947 (the early antiques cut-off) and 1973 (CITES). Today new trade in ivory is prohibited or severely restricted in most countries.

Working techniques

Historical ivory working followed several techniques:

Carving. With fine iron tools, later with dental-type micro tools. This permitted very fine detail work - eyelids, facial creases, cranial sutures, the smallest inscriptions.

Turning. On the lathe, thin ivory discs could be produced, used as picture supports or as cabochon substitutes.

Engraving. With fine gravers, inscriptions, symbols and small pictures were worked into the surface. The lines were then rubbed with ink or soot to increase the contrast.

Inlaying. Small pieces of ivory were inlaid into wooden or metal frames - for instance as light accents in dark mourning pendants.

Painting. Smoothly polished ivory plates formed the picture support for miniature paintings - the most important application in mourning jewellery in the 18th and 19th centuries.

Legal status today

International trade in ivory has been strictly regulated by the CITES convention since 1973. Important points:

• Before 1947: pieces made before this date are "pre-Convention" and legally tradable with proof of antique status
• 1947–1990: pieces require an EU marketing certificate (Article 10)
• After 1990: no legal trade within the EU
• Mammoth ivory: not CITES-protected, freely tradable - the most important legal alternative
• Walrus ivory: regulated in some countries (USA, Canada)

When historical ivory pieces are inherited (from grandparents, great-grandparents) the legal position is mostly uncritical - family property without intent to sell is not regulated. For a sale or at auction, an assessment with determination of the Schreger lines and proof of age is required.

Alternative materials

Several materials are used today as ivory alternatives:

Mammoth ivory. Subfossil material from the Arctic permafrost, above all Siberia and Alaska. Visually almost identical to elephant ivory, often with darker honey tones. CITES-free, fully legal. Price: about €50–150/kg in the raw state.

Tagua nut ("vegetable ivory"). The fruit of the South American Phytelephas palm; after drying very hard and similar to ivory in colour and grain. Ecologically unproblematic, very inexpensive. Today used above all for buttons and small carvings.

Bone. Considerably more porous, less finely workable, but inexpensive and unproblematic. Acceptable for vernacular carvings.

Synthetic resins. Various synthetic resins imitate the appearance of ivory. Often visually recognisable (no Schreger lines, different refraction of light), but practical for stage jewellery and imitations.

Ivory in the modern memorial market

In the current memorial jewellery market ivory plays no relevant role:

• Antique pieces (pre-1947, with proof) are tradable as collectors' objects; they are occasionally integrated into modern memorial settings (a gold mount around a historical ivory medallion)
• New pieces made of elephant ivory cannot be legally produced in the EU
• Mammoth ivory pieces are a small niche, above all for historicising restoration contexts
• Tagua nut pieces are ecologically and ethically unproblematic and are occasionally offered as a material for keepsake pendants

In present-day memorial jewellery practice the historical position of ivory (as a fine picture support and as a light, contrasting material) is taken over by mother-of-pearl, pale freshwater pearls or white enamels.

Care of historical ivory pieces

Antique ivory pieces are delicate:

• Keep humidity constant (40–55%) - air that is too dry leads to cracks
• No direct sunlight - UV accelerates yellowing
• No solvents (alcohol, acetone, ammonia) - these attack the dentine structure
• Cleaning only with a soft, slightly damp cloth; consult a conservator in the case of heavier soiling
• Storage in acid-free packaging, never in bags containing PVC

With historical memorial pendants bearing an ivory miniature portrait particular care is required - the watercolour painting is extremely sensitive to moisture. Such pieces should never be opened, never cleaned and ideally kept only at controlled humidity.