Estimating the Age of Whale Teeth from Natural Dry-Out Cracks

This guide outlines one basic method used to estimate the age of authentic whale teeth. Scrimshaw collectors are always interested in knowing whether a whale tooth is:

Antique = more than 100-years old (>100-yo);
Vintage = (50-yo to 100-yo); or
Modern = less than 50-years old (<50-yo).

Other, more complicated factors (NOT discussed here) are involved in narrowing or confirming the age of whale ivory.

All whale teeth have a natural skirt at the base of a tooth, which protects the living nerve root. Young teeth have a blade-thin & knife-sharp skirt edge [image #1]. In contrast, the tooth skirt of teeth from old whales can be short & thick, or nearly non-existent [image #2]. Most antique scrimshawed whale teeth were taken from mature Sperm whales, where as most vintage & modern scrimshawed whale teeth were taken from any Sperm whale within reach of a harpoon gun. It is probable that more teeth were scribed from 1950 through 1982, than in the 150-years prior, and most of these latter teeth were 8-ounces or less. In all of the following images, note that size differences often reflect age differences.

Any tooth NOT "in situ" (original mouth location) immediately begins to dry-out. Two symptoms are surface hardening (becoming brittle) and cracking (due surface shrinkage). With age, both characteristics become more pronounced.

For Sperm whale teeth, the surface hardening happens within a few months of removal from the whale. Victorian-era scrimshanders working on fresh teeth could easily use common tools at hand, such as pocket knives & sail needles, on the soft-surfaced teeth. Contemporary scrimshanders use razor-sharp Xacto blades and needle-sharp tungsten scribing tips. Even then, scribed lines on the brittle surface of an aged whale tooth [image #3] are actually a series of linked, minute, shatter-pits, just like scratching glass.

In whale teeth, "age-cracking" progresses very slowly, and may take decades before becoming apparent. A thin tooth skirt may show age-cracking years before a more stout tooth from the same whale. Using dry-out cracks to determine age is only a guide, and does not take into account environmental conditions prior to evaluation. To counter dry-out cracking, I store all of my scrimshawed whale teeth in a hermetically-sealed glass display case, with a shot-glass of water inside.

Victorian-era scrimshanders cut-off a 1/2-inch (or more) of the skirt edge. This left a blunted, thicker lip, which physically resists dry-out cracking, and allowed the whale tooth to stand, or self-display vertically. On antique whale teeth, these blunted skirt edges often display a "crazed" cracking pattern [image #4]. Losing a 1/2-inch on a 7-inch tooth is nearly negligible, but modern scrimshanders most often scribe 4-inch to 6-inch teeth, and purposely do not shorten teeth for any reason.

Traditionally,

a whale tooth skirt with NO dry-out cracks is considered to be <25-yo [image #1];

a whale tooth skirt with one or two small, fine, dry-out cracks is <50-yo [image #5];

a whale tooth skirt with several dry-out cracks is 50-yo to 100-yo [image #6];

a whale tooth with multiple dry-out cracks, and/or "crazing" is >100-yo [image #4 & image #7].

Dry-out age cracking can also be observed across the median line between the hard core-tip (Dentine) aka Golden Crown, and the outer layer (Cementum) [image #8]. The line count is roughly the same as for the tooth skirt.

Patina (tooth color) naturally deepens with age, but is also heavily influenced by environmental conditions. A tooth stored in a drawer for 100-years could be just as ivory-white as a new tooth. On the other hand, a 25-year old tooth displayed on the open shelf in the home of a smoker could have deep, rich, brown patina from the absorption of tar from cigarette smoke. A similar color can be obtained (or enhanced) by immersion in tea or coffee. Usually, only in-hand evaluation can reveal false patinas, so a written guide on patina is not as useful as this guide on dry-out cracking. Correctly assessing the age of a whale tooth through properly interpreting both dry-out cracking and patina, depends on accumulated experience as much as knowledge. The more whale teeth you view, the more experience you will acquire. And remember: you can NEVER see too many whale teeth.