The Seiko Quartz Astron 35SQ was unveiled in Tokyo on 25 December 1969 after about ten years of research at Suwa Seikosha, now Seiko Epson. Seiko calls it the world’s first mass-production quartz wristwatch. The case is 18k yellow gold and 35 mm in diameter, with a textured finish, a cushion-like profile and a champagne dial with applied baton indices and a central seconds hand. Calibre 35SQ uses an XY-cut quartz crystal oscillating at 8,192 Hz, a hybrid integrated circuit built from 76 transistors and 29 capacitors on a ceramic substrate, a miniature stepping motor to drive the hands, and 8 jewels. Seiko rated its accuracy at plus or minus 5 seconds per month, about one minute per year, with a battery life of a year or more.

The Astron was priced at 450,000 yen, about the price of a medium-sized car at the time, and roughly 100 gold examples sold within a week of launch. It was aimed at the luxury market, yet its battery-powered technology soon made precise timekeeping cheap and widely available. The watch is recognised as an IEEE Milestone in electrical engineering. Seiko later revived the name: in 2012 the Astron became a solar-powered GPS satellite-time watch, and in 2019 the brand marked the 50th anniversary with limited editions, including an 18k gold model of 50 pieces that echoes the original case with engraving by Epson’s Micro Artist Workshop.

Historians and collectors treat the 35SQ as one of the most consequential watches of the 20th century, since it set off what became known as the quartz crisis for the Swiss industry. Its short production and gold case make original examples rare, and they attract strong attention when they appear; a non-running piece with serial 9N0001, from the first November 1969 batch, drew heavy bidding when it was listed on Yahoo Auctions Japan in December 2024. Some enthusiasts note the irony that a watch meant as a luxury object ended up democratising accuracy. The original Quartz Astron 35SQ is no longer produced; the Astron name continues in Seiko‘s current GPS solar collection.