Mount Tsukuba Granite: Balancing Heritage and Sustainability
Around Mount Tsukuba in Ibaraki Prefecture, Japan, lies a historically significant quarrying area. In 2024, the Tsukuba massif granite of the Mt. Tsukuba Area Geopark was certified by the International Union of Geological Sciences (IUGS) as one of the first 55 IUGS Heritage Stones [1] – natural stones recognized not only for their geological value but also for their integral role in human culture through their leverage in architecture and monuments.
A History Rooted in Stone
Archaeological evidence indicates stone tool production in the area dating back to ancient times. The local stone industry began to flourish around seven centuries ago, with the creation of stone monuments, statues, and buildings. [2] The unusual rocks of the Tsukuba Massif have been protected by local people as a place of worship for centuries, and in the 13th century, granite from the area began to be used to create stone Buddhas and Gorinto (five-ring pagodas). [2]
Facing a Sustainability Crisis
Despite its cultural significance and recent international recognition, the area’s stone industry is facing a sustainability crisis. According to Kaoru Sugihara, a geologist and former professor and specialist with the Mt. Tsukuba Area Geopark Promotion Council, the number of members in the area’s three stone producers associations had fallen to less than a quarter of its 1992 level in 2024, due to declining demand for stone in construction and for tombstones, coupled with increased imports of foreign stone. [1]
Revitalization Efforts: Tours and Local Pride
To revitalize the industry and foster local pride, the council organized a series of bus tours in the fall of 2025. [1] The first tour, held on November 12, visited a casting factory, a sake brewery, and a quarry in the Maka-be, Kasama, and Inada districts. The geopark’s theme, “stone, soil and water connecting nature and people,” was reflected in the tour’s destinations. The Kotabe Chuzo casting factory utilizes molds made of clay derived from local weathered granite to produce temple hanging bells. Nishioka Honten brews sake using local groundwater rich in minerals from granite. [1]
A second tour on November 15 explored structures in Tokyo built with Tsukuba massif granite, including Tokyo Station Marunouchi Honya, Marunouchi Tokyo Station Square, and the Nihonbashi bridge. Participants also enjoyed a panoramic view of the Tokyo metropolitan area from the Tokyo Skytree Tembo Deck. [1]
Feedback from participants, gathered through a post-tour survey, indicated satisfaction, particularly with access to sites not typically open to individual visitors. [1] Yuji Ito, the secretary-general of the Mt. Tsukuba Area Geopark Promotion Council, highlighted the value of insights provided by local business owners and professionals. The tours also incorporated local gastronomy, featuring Japanese yam, a regional delicacy.
Innovation Through Product Development and Waste Reduction
The council is collaborating with local stone suppliers to develop new products, such as the Gura Gura-Nite stone toy – a set of granite and gabbro stones designed for stacking, building, or display. [1] This initiative aims to utilize scrap materials, improve craftsman skills, and address the issue of stone waste, which typically exceeds 70% of quarried material. [1] Sugihara expressed hope that these efforts will encourage further collaboration and innovation across various fields.
The Mt. Tsukuba Area Geopark is part of a broader initiative by the International Union of Geological Sciences (IUGS) to create a worldwide inventory of geological heritage sites, recognizing the role UNESCO Global Geoparks can play in this process. [3] The area gained Geopark status in late 2016, acknowledging its geological landscapes and cultural heritage. [4]
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