Our Story

Pistachio shells are “ingenious.” They’ve been lauded for their extraordinary strength-to-weight ratio, achieved by a cellular structure researchers call a “holy grail of materials science.” In fact, they may one day be used to make shock-absorbing items like safety helmets. 

Admittedly, I didn’t know any of that around 2010 when I saved some discarded pistachio shells, bought a small drill, and began experimenting. I did know I loved turning the shells into sculptural earrings that were so lightweight I could barely feel them. (Lightweight earrings are generally considered to weigh between 2 and 4 grams per earring; TACHIO’s earrings range from 0.3 to 1.3 grams per earring.)

Roughly fifteen years later, when I finally dusted off that drill and pulled out several bags of shells I’d been squirreling away, I approached the process with a renewed curiosity and intensity. What else could these sturdy wood-like shells transform into?

TACHIO (pronunciation: pistachio) is my ongoing answer to that question.

And as I started creating more elaborate designs, objects, and embroidery, I kept getting another question from people: How often do they break when you’re drilling them?

The answer is very rarely. Like, once-in-a-blue-moon rarely.

But now I had another question: Why? Why don’t they break more often? Why are they so lightweight yet so tough?

The Pistachio Shell: Nature’s Lightweight Armor

It turns out scientists have asked the same question. A pistachio shell is designed to protect its seed (what we call a nut is technically the seed of a drupe aka stone fruit). Instead of relying on mass, the pistachio shell achieves its strength from its dome-like curvature and 3D interlocking cells. While similar in composition to wood, pistachio shells aren’t prone to splitting like traditional tree wood; their dense stone cells lock in with roughly fourteen neighboring cells like a microscopic jigsaw puzzle, distributing stress evenly rather than along a single linear grain line.

Remarkably, when researchers looked at the edges of fractured pistachio shells under a microscope, they found that most cells had “never separated from their neighbors.” In fact, they could see that “splitting the pistachio shell material had required slicing through individual cells."

I find this inspiring on a few levels. And I think about it now as I work—especially when I’m drilling more than sixty tiny holes into a single shell that maintains its structural integrity, never cracking or shattering.

Process and Materials: From Raw Shell to Finished Object

Every TACHIO piece undergoes a meticulous, multi-step refining process.

Prep & Surface Tuning: Raw, selected shells are systematically cleaned, dried, drilled, and sanded.

Sealing & Protection: To safeguard against wear and moisture, most pieces are sealed with a nontoxic, plant-based varnish followed by an extremely thin layer of microcrystalline wax, giving the surface a durable sheen.

Embroidery: For textile pieces, threads are selected based on the foundation material. Priority is given to natural threads, but sometimes polyester/elastic threads are necessary. For the jewelry in the cerulean stitch series, a polyester thread is required because the thread ends are heat-sealed to keep the in-shell stitching secured.

Assembly & Hardware: For jewelry, elements are joined with metal hardware, including stainless steel, 316L surgical steel, gold-plated 316L surgical steel, and solid .925 sterling silver.

Thank you for being here. You can explore our catalog, review our product care guide, and subscribe to our mailing list below.