Casio has given its square G-Shock plenty of metal finishes and color treatments. The GMW-B5000SB-1A2 takes a different approach: four lab-grown blue sapphires set into the bezel.
Price: $770
Where to Buy: Casio
The stones sit in the familiar dimples surrounding the display, adding flashes of blue to an otherwise black watch. But this is more than a decorative update. Casio modified the GMW-B5000’s shock-resistant construction to accommodate the gemstone settings.
Underneath them, the watch retains Tough Solar charging, Multiband 6 radio-controlled timekeeping, Bluetooth connectivity, and 200-meter water resistance.
Four sapphires, not sapphire glass
The GMW-B5000SB belongs to Casio’s Blue Rose Project, which uses blue sapphire gemstones to represent its pursuit of unconventional design and toughness. Four round brilliant-cut, lab-grown sapphires occupy the bezel dimples around the square display.
There is an important distinction here: the sapphires are decorative stones, not the watch’s crystal. Mineral glass protects the digital display.
The stainless-steel bezel has black ion plating, with mirror-polished and hairline-finished surfaces. Blue detailing around the display echoes the gemstones, while a negative LCD and black soft urethane band keep the rest of the watch dark. Despite the Full Metal designation, this version does not come with a steel bracelet.
The stones look like accents rather than the centerpiece of a conventional jewelry watch. Their placement makes use of an existing part of the square G-Shock design instead of introducing an entirely new shape.
How Casio mounted the gemstones
Adding gemstones raises an obvious question for a G-Shock: how do you protect them from impacts?
Casio says it updated the GMW-B5000’s full-metal shock-resistant structure specifically for these settings. Holes bored through the bezel dimples accommodate stainless-steel mounting bases and rubber buffering components that support each gemstone from underneath.
According to Casio, that arrangement preserves the original shock-resistant performance while securing the sapphires. We haven’t independently tested that claim, but the mounting system is a more interesting detail than simply attaching four stones to an existing bezel.
Familiar G-Shock features underneath
The GMW-B5000SB measures 49.3 × 43.2 × 13 mm and weighs 98 g. Its case and bezel are stainless steel, and water resistance is rated to 200 meters.
Tough Solar handles charging. Casio specifies approximately 10 months of normal operation after a full charge without further exposure to light, or approximately 22 months when stored in total darkness with power saving enabled.
Multiband 6 receives supported radio time-calibration signals, while Bluetooth connects the watch to the Casio Watches smartphone app for automatic time adjustment and settings. Without radio calibration or mobile linking, rated accuracy is ±15 seconds per month.
The app provides approximately 300 world-time cities plus a user-added location, reminders, Time & Place logging, and a phone finder. On the watch itself, features include five world times, a stopwatch, a 24-hour countdown timer, five daily alarms, and a white Super Illuminator LED backlight.
What makes this version different
The sapphires do not add a new timekeeping feature. Their appeal is visual, and the most compelling part of the design is how Casio integrated them into the existing bezel.
Price: $770
Where to Buy: Casio
For someone who likes the metal square G-Shock but wants something less conventional, the GMW-B5000SB-1A2 offers a distinctive variation. Its signature detail isn’t a larger display or another connected feature. It’s four small blue stones, and the changes Casio made to give them a place in a G-Shock.
