Tortoiseshell is the mottled amber, honey and near-black pattern that once came almost entirely from the hawksbill sea turtle, not a land tortoise; the turtle's shell is covered in plates of keratin called scutes. For almost all new products it is now a pattern rather than a material: the hawksbill has been on CITES Appendix I since 1977, which bans international commercial trade in its shell. A tortoiseshell phone case like COCOMII's carries a printed tortoiseshell pattern on a glossy polycarbonate and TPU shell with a built-in MagSafe magnet ring. This guide is COCOMII's own, so the only cases it names are ours.
What Is a Tortoiseshell Phone Case Made Of?
A tortoiseshell phone case today is almost always an imitation: a plastic case that carries the tortoiseshell pattern, either printed on its surface or colored into the material itself. COCOMII's is printed, so no turtle shell is used: the pattern is printed in a glossy finish on a polycarbonate and TPU shell with a built-in MagSafe magnet ring, and the case is 10-foot drop tested. COCOMII also lists raised edges around the screen and camera and reinforced corners as part of its construction.
The shape is a rectangle, with flat sides and right-angle corners; the guide to the rectangle shape explains why that silhouette works. In Chestnut, Amber and Ivory the case is made for the iPhone 18 Pro Max/17 Pro Max and the iPhone 18 Pro/17 Pro. Across all its colorways it covers select iPhone models back to the iPhone 12; Tangerine and Mandarin are made for some older iPhones only.
Is Tortoiseshell Real?
Tortoiseshell is a real material, the shell of the hawksbill sea turtle, and antiques made from it survive. New tortoiseshell sold legally in the United States today is an imitation in acetate, resin or print, and that includes COCOMII's case, which carries a printed tortoiseshell pattern.
International commercial trade in hawksbill shell has been banned since 1977, when the hawksbill was listed on Appendix I of CITES, the convention that regulates international trade in wild animals and plants, as TRAFFIC's 2021 report on the shell trade sets out. The year 1973 is often given for the ban, but that is when the treaty was signed; it came into force in 1975.
US protection is older: the hawksbill has been listed as endangered since 1970, according to NOAA Fisheries, and US Fish and Wildlife Service guidance says endangered species, the hawksbill among them, generally cannot be sold across state lines or international borders. The main exception is a documented antique at least 100 years old that meets the conditions of the Endangered Species Act.
Other countries differ. Japan's traditional tortoiseshell craft, bekko, still works legally from stockpiles built up before the country's imports ended in the early 1990s. Illegal trade continues too: the US Fish and Wildlife Service says a significant illegal trade persists, and the IUCN lists the hawksbill as Critically Endangered.
For a shopper, the rule is short. A new phone case, comb or pair of glasses sold in the United States as turtle shell is either illegal or mislabeled. The honest version of this pattern simply calls itself a pattern.
Is Tortoiseshell From a Tortoise or a Turtle?
From a turtle. The material came mainly from the hawksbill, a sea turtle of tropical reefs, not from a land tortoise. The hawksbill's shell is armored with thick, overlapping scutes made of keratin, the family of tough proteins that also forms hair and fingernails, and those plates are what craftsmen cut, softened and polished. The name is a misnomer that stuck, which is why conservation groups such as SEE Turtles prefer the word turtleshell. Tortoiseshell also names a black and orange cat coat and a group of butterflies, as the dictionary entry notes. On a phone case it means the pattern, and shoppers who search for a turtle shell phone case mean the same thing.
Where Did Tortoiseshell Come From?
Tortoiseshell was already a luxury in ancient Rome and stayed one for more than two thousand years, prized for its glow and for how well it could be worked. The shell is translucent, and as the Pitt Rivers Museum describes, it is a natural thermoplastic: warmed, it could be molded, and pieces could be fused without a visible seam. That is how it became combs, hairpins, snuff boxes, inlaid furniture and spectacle frames, the very combs and frames that acetate still imitates today.
The milestones, in order:
- Early 1st century BC, Rome. Pliny the Elder's Natural History names Carvilius Pollio, a man with a gift for inventing luxuries, as the first to slice the shell into thin sheets and veneer beds and cabinets with them.
- Late 1600s and early 1700s, France. André-Charles Boulle (1642-1732), granted lodgings in the Louvre by the king in 1672, perfected the inlay of tortoiseshell and brass that still carries his name, a style the Metropolitan Museum of Art traces in its essay on French furniture of the period.
- Early 1800s. Dyed horn becomes a common, cheaper stand-in for the shell, according to the Museum of Design in Plastics.
- 1870. John Wesley Hyatt and his brother Isaiah patent celluloid, the first commercially successful plastic, and it is soon fashioned into imitation tortoiseshell combs and eyeglass frames, as the Science History Institute recounts.
- 20th century. Cellulose acetate, less flammable and easier to work than celluloid, becomes the standard plastic for eyewear, tortoiseshell frames included, a history traced by the optical trade magazine 20/20.
- 1977. The hawksbill is listed on CITES Appendix I, which bans international commercial trade in its shell.
- Early 1990s. Japan, by far the largest buyer and the holder of a reservation to the treaty, ends its legal imports, as TRAFFIC's report details.
The shell trade did not stop when plastics arrived. For roughly a century the copies and the shell were sold side by side, and the toll was heavy: a 2019 study in Science Advances estimates that about nine million hawksbills were killed for their shell between 1844 and 1992, with most of the shell bound for Japan.
What Is Imitation Tortoiseshell Made Of, and How Can You Tell?
Imitation tortoiseshell has been made from stained horn, early plastics such as celluloid, cellulose acetate, acrylic and resin, and, on phone cases, a printed pattern on a synthetic shell. The Museum of Design in Plastics also lists casein, phenolic resin, polystyrene, PVC and polycarbonate among the plastics that have carried the look. The main ones compare like this:
| Material | What it is | When | How it is usually recognized |
|---|---|---|---|
| Hawksbill shell | Keratin scutes from the hawksbill sea turtle, softened with heat and pressed | Antiquity to the early 1990s in legal international trade; antiques, and Japan's stockpile craft, today | Fine grains of pigment and thin layers under magnification; documented provenance |
| Stained horn | Animal horn pressed thin and dyed with a mottle | Common by the early 1800s | Parallel fibers under magnification |
| Celluloid (cellulose nitrate) | The first commercially successful plastic, colored before molding to create the mottle | From the 1870s | Uniform under magnification, like other plastics; flammable, so never heat-tested |
| Cellulose acetate | A plastic made from cellulose, from wood pulp or cotton, often cut from block sheets in which the pattern runs through the material | 20th century to today; the eyewear standard | Usually labeled as acetate; in block acetate the pattern shows on cut edges |
| Acrylic or resin | Cast or molded plastic colored to imitate the mottle | Today | Even and uniform under magnification, like other plastics |
| Printed pattern on a synthetic shell | An image of the pattern printed onto a plastic case, such as COCOMII's polycarbonate and TPU shell | Today | Sold and labeled as a print; the pattern sits on the surface |
There is no reliable eye test. Good acetate and old horn can look very like the shell, and a 2024 identification study notes that telling them apart by eye can be difficult, which is why conservators work under magnification and confirm with laboratory methods such as infrared spectroscopy. Home tests with a hot pin, a flame or a solvent damage the object, and celluloid is flammable, so leave them alone. For an inherited piece, ask a conservator; for anything new, buy what is clearly labeled as a pattern.
What Color Is Tortoiseshell? The Tones Explained
Tortoiseshell is a translucent amber ground clouded with irregular brown and near-black mottling, and its colors came from the turtle itself. The pattern was not a dye or a painting: the pigment sits inside the keratin, and because the plates are translucent, amber seems to glow over the darker patches beneath it. The US Fish and Wildlife Service describes adult hawksbill shells as brown with splashes of yellow, orange and reddish brown.
Makers describe the pattern by tone, from light to dark, and the names are conventions rather than a standard:
- Blonde. The palest tortoiseshell: cream and pale honey.
- Honey or amber. Golden amber with brown mottling, the classic middle tone.
- Dark, often called Havana. Chocolate brown and near-black, with only glimpses of amber.
In eyewear, Havana and tortoise are often used interchangeably, as 20/20 has noted, though some retailers use Havana for a lighter tan, so judge the photo rather than the name.
COCOMII's tortoiseshell case covers all three tones for current phones. Ivory is the blonde tone, a pale cream ground with dark spots; Amber is the honey tone; Chestnut is the dark, Havana-style tone.
Which tone suits which wardrobe is a pairing question, and our guide to what colors go with tortoiseshell matches each tone to the colors and outfits it works with.
Why Has Tortoiseshell Lasted?
Because the pattern outlived its material. Celluloid copied the look from the 1870s while the shell trade carried on beside it. By the time the shell trade closed, imitation frames had made the look an everyday sight, so nothing about it had to change: the copy became the classic.
It has lasted, we think, because the pattern is warm and irregular enough to stay in the background of a day. The mottling never settles into a motif, so it does not announce itself the way a logo does, and it still reaches us mostly through things carried every day and close at hand: glasses, hair clips and a phone case, held on an ordinary autumn walk.
How to Judge a Tortoiseshell Print
Once you know a phone case carries a print, the useful question is whether the print is a good one. Four checks separate a pattern worth carrying from a flat copy.
- Depth. Hawksbill shell lets light in, so its lighter tones appear to float over darker clouds beneath them. A good print layers its tones to suggest that depth; a poor one looks like a photograph of the pattern, flat and airless.
- Irregularity. The shell's mottling was irregular, so a print should not repeat itself. Hold the case at arm's length and look for a repeating tile. If you can find the seam, so will everyone else.
- Tone balance. Whatever the tone, both light and dark should be present. A print that drifts into solid brown or flat orange loses the contrast that makes it read as tortoiseshell.
- Finish. Finished tortoiseshell was typically polished to a gloss, so to our eye a glossy print is the more faithful one; a matte surface tends to look flatter.
Use the checks on any tortoiseshell case, ours included. COCOMII's tortoiseshell MagSafe rectangle case is printed with a glossy finish in Chestnut, Amber and Ivory for current phones, and the tortoiseshell collection shows every colorway and the iPhone models each one is made for.
Frequently Asked Questions
Is tortoiseshell the same as tortoise shell?
Yes. Tortoiseshell, written as one word, is the dictionary headword for both the material and the pattern; tortoise shell, written as two words, is a common variant that can also mean the literal shell of a tortoise. On a phone case, either spelling describes the pattern.
What is another name for tortoiseshell?
For the material, conservation groups prefer turtleshell, since it came from a sea turtle rather than a tortoise, and in Japan the traditional craft is called bekko. For the pattern, you will also see tortoise print, tortoise or tort, and in eyewear the darker tones are often called Havana.
What is the difference between tortoiseshell and leopard print?
Tortoiseshell is a mottle: soft, irregular pools of amber, honey and near-black taken from the look of sea turtle shell. Leopard print copies a big cat's coat, with dark rosettes and spots on a tan or golden ground. COCOMII prints both on the same polycarbonate and TPU shell, and its leopard print guide explains that pattern in detail.
How do you care for a tortoiseshell phone case?
A soft cloth is usually all it needs. COCOMII's glossy finish wipes clean easily, so fingerprints and everyday marks lift off quickly. As with any phone case, keep it out of high heat, such as a car dashboard in direct sun. Antique pieces made of hawksbill shell are a different matter and belong with a conservator.
