A final thrust of the crowbar cracked the wooden crate open, and the architect, the anthropologist, and the mortar expert leaned in to look at the oddity that had drawn them to an out-of-the-way warehouse on a glimmering spring morning.

This much was clear: It was a 3-foot-by-10-foot section of timeworn brick wall, its predictable rows abruptly interrupted by three distinct, deliberate-looking triangular shapes. But beyond that, there were only questions.

Painstakingly preserved from a 175-year-old building in lower Manhattan, the brickwork symbol is — at least to some — a smoking gun in a tantalizing historical whodunit. The setting conjures both New York City’s mercantile past and its post-September 11 future. The cast of characters includes the founder of a prominent American corporation. And the trail of clues has veered enticingly close to a “Da Vinci Code”-like territory of clandestine symbols.

Could the design be a cryptic marker of mystical beliefs? A tradesman’s signature or a bit of architectural shorthand? Simply an artistic add-on or a creative way to patch a hole? Speculation — some backed with scholarly authority — has swirled around the possibilities, generating enough gravity to pull in community leaders and persuade a developer to spend $13,000 to save the artifact from demolition.

The symbol’s significance may never become clear, and recent tests have cast a shadow over its glint of history. Still, enthusiasts say the artifact’s value lies in the questions it has raised, regardless of the answers.

“Whether you believe in this stuff or not, it suggested so much and pointed to so many things,” the volunteer historian who pushed to preserve the symbol and probe its meaning, Alan Solomon, said this week. “It’s just a cabinet of curiosities.”

The design is simple, but clearly no accident. It centers on a triangle framed with a strip of mortar, framed by two rougher triangular forms.

Whatever its origin, the symbol sat unheralded for years inside 211 Pearl St., at the edge of New York City’s financial district. Mr. Solomon, who works for a Brooklyn vintage-lumber dealer, spotted the artifact several years ago, while engaged in a broader effort to save the 1832 building.

Most was ultimately demolished to make way for a parking garage for a new apartment tower, financed in part with tax-exempt bonds intended to spur redevelopment after the September 11 terrorist attacks. But the façade and the brick symbol were saved.

City tax records show the onetime warehouse was built for William Colgate — the deeply Christian soap entrepreneur who founded what is now Colgate Palmolive Co. A spokesman says Colgate Palmolive has no record that the company, then headquartered elsewhere in Manhattan, used the Pearl Street building. But Colgate prized it enough to make special note of it in his will, Mr. Solomon said.

To Mr. Solomon and some historians, Colgate’s ties to the building fueled a theory that the brickwork pattern had some Christian resonance.

The triangle has traditionally been used to represent the Christian concept of the Holy Trinity. And some scholars thought the Pearl Street symbol evoked esotericism — efforts to delve for divine meaning in numbers, geometry, nature, and elsewhere. The symbol was even the subject of a presentation at an academic conference in Amsterdam in 2005.

No one has claimed to be sure of the artifact’s historical merit. But many who have visited the object say they feel its pull as an imprint of human inventiveness, if nothing else.

“No matter how we slice it, it’s meaningful,” Rocco Leonardis, an architect and brick aficionado, said as he looked it over in its warehouse crate.