About Nautilus Shells and Mounts
Every object in this database consists of a nautilus shell (from the mollusk Nautilus pompilius) transformed into an artistic object by the transformation of the shell and/or the addition of a framing mount. There are many examples of nautilus shells transformed into useful objects, or mother-of-pearl (from nautilus shells or other sources) assemblies or inlay work, as well as examples of other mounted shells, which have been excluded. The nautilus mollusk lives in the Indo-Pacific, generally around Indonesia, and their shells were imported as curiosities to Europe as a by-product of the Spice Trade from the late medieval period through the early modern.
The working and assembling of nautilus shells and their mounts include several techniques which may have been completed by multiple hands. Visual evidence suggests that the shell and the mount were generally worked separately, by different artists, because the styles and motifs of decoration don't match, because the mount often obscures decoration on the shell (rather than carefully framing and showing it off), and the techniques are different. In some cases, the mounts are later assemblies of pieces from different artists (like the foot and the mount were made separately). Likewise, the several techniques applied to the shells may have been done by a single artist or several.
European metalworkers mounted the shells, most often in gilded silver, but also in other metals, or included jewels, stones, enamel, and other materials in the metalwork. There is no evidence that artists elsewhere in the world mounted nautilus shells. The transformation of the shells, however, appears to have happened in both Europe and Asia. Rumphius (1705/1999) described Asians stripping shells (he was in Ambon in the Indonesian archipelago), and there is early modern textual evidence that suggests that Chinese or Indian artists (these terms are imprecisely used in the period) may also have decorated the shells. This evidence is confoundingly ambiguous. I'm unaware of any decorated shells in Asia, so this appears to have been strictly an export market.
Common terminology
The media of these objects is described with "tags." I made an effort to smooth (standardize) this data so that items with very similar media can be grouped in the "Browse by Tag" feature. If an item has a secondary material, that is generally indicated as "with X" to differentiate from items that are primarily of that material. I've used "jewels" as a catch-all for precious, semi-precious, and not precious stones, and I may add more granularity at a later date.
Unworked: Nautilus shells that are unworked are in their natural state, which has a white and orangey-brown striped exterior and visible mother-of-pearl inside the shell's opening.
Stripped: The external white and brown layer has been removed to expose the mother-of-pearl, now visible both inside and outside the shell. This is accomplished by soaking the shell in an acidic solution, a method known both in Southeast Asia where the shells were collected (Rumphius 1705/1999 describes Ambonese artisans using a vinegar solution) and in Europe since the medieval era.
Selectively stripped: The external white and brown layer of the nautilus shell has been selectively removed, usually to produce a decorative effect. Presumably, the same acid bath technique is used, but carefully applied, and some carving may also be involved. Mette 1995 refers to this as 'flat relief' and it may also involve engraving into the exterior level that remains.
Engraved: The artist engraves/cuts lines into the surface of the mother-of-pearl of the shell or alternatively into the remaining exterior level in a selectively stripped shell (Mette 1995 refers to this as 'flat relief'). This requires a sharp tool, and also delicacy, as the shell (especially when fully stripped) is quite fragile. The technique is similar to engraving in metal plates for printing on paper, and so it is possible that some of the anonymous artists engraved plates or other surfaces as well. The engraved lines become more visible by rubbing pigment into them - most commonly black pigment has filled the engraved lines, and this may be original, added later, or cleaned off later.
Cut through: I'm using this term to bring together several related features where the artist has cut through the shell surface and removed pieces of shell. Common uses are to reshape the shell opening; to pierce through the curve of the shell allowing a decorative view inside; the opening of the internal curve of the shell, in many cases creating a 3D helmet or cutting or engraving a coat of arms that are visible when looking into the mouth of the shell.
Application of materials: Some shells have been decorated by addition of material, such as jewels, painting or gilding the surface, or the addition of pigment.
Gilded silver: This is the most common medium for the mounts. The mount was formed of silver, in the early modern period mined in what is now Germany, Mexico, and Peru. Silver tarnishes, so applying a thin layer of gold to the finished mount ensures a consistent and rich finish.