PHOTO ESSAY: Scottish island Ailsa Craig is the granite source for Olympic curling stones

Ailsa Craig is an uninhabited isle off the coast of southwest Scotland and the source of the super-dense granite used to make curling stones for the Winter Olympics. It features both “common green” granite comprising the body of the stone and the “blue hone” granite that forms the running surface.

Local company Kays Curling makes all the the curling stones for the Milan Cortina Winter Games. It has a history with the Olympics dating back to the first winter edition in 1924 in Chamonix, France. Kays produces up to 2,000 stones per year and Canada is its biggest market. Asian countries have been increasing their orders.

This is a documentary photo story curated by AP photo editors.

AP photography: https://apnews.com/photography

Dog walkers stand on the beach at Girvan with the granite island of Ailsa Craig in the background in Scotland, Thursday, Nov. 13, 2025. (AP Photo/Alastair Grant)

A finished curling stone in a store room at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

A groove is made on a curling stone by a craftsman at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

Curling stones await further machining during being manufacture at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

A craftsman works on machining Ailsa Craig Common Green granite into the shape of a churning stone at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

Ailsa Craig common green granite curling stone blanks are dried under a heater as they wait further machining at the Kays Curling stone factory on Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

A craftsman uses calipers to measure the amount of a curling sone that has contact with the ice, during a quality control phase at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant,)

Blue Hone granite is machine cut from block of the rock at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

A craftsman uses a stonecutting machine to slice Blue Hone granite blocks which are then used in curling stones at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

Blue Hone granite blocks are prepared to be used as part of a curling stone at Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

Granite rock that has been used to create curling stone blocks lies outside Kays Curling stone factory in Mauchline, Scotland, Tuesday, Nov. 11, 2025. (AP Photo/Alastair Grant)

Jim English, Kays Curling Managing Director, looks at a bolder of granite on the island of Ailsa Craig, off the coast of Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

Old quarry equipment rusts, with the lighthouse in the background on Ailsa Craig island, off the coast of Scotland , Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

A danger sign near the steep cliff and granite quarry on Ailsa Craig island off the coast of Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

Jim English, Kays Curling Managing Director, shows the amount of the mineral feldspar in a pebble of granite on the island of Ailsa Craig, off the coast of Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

The steep granite cliffs on Ailsa Craig island off the coast of Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

The lighthouse is seen from the small boat taking environmental officers to Ailsa Craig island, Scotland , Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

Seals swim in the surf off the island of Ailsa Craig off the coast of Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

A small boat carrying environmental officers heads towards the granite island of Ailsa Craig, Scotland, Monday, Nov. 10, 2025. (AP Photo/Alastair Grant)

The island of Ailsa Craig, where the two types of granite, Common Green and Blue Hone, that are used to make curling stones is quarried from, is seen from the beach at Girvan, Scotland, Thursday, Nov. 13, 2025. (AP Photo/Alastair Grant)

MENLO PARK, Calif.--(BUSINESS WIRE)--Dec 18, 2025--

Tutor Perini Corporation (NYSE: TPC) (the “Company”), a leading civil, building and specialty construction company, announced today that its subsidiary, Rudolph and Sletten, has been awarded a contract by UC Davis Health for the Central Utility Plant (CUP) Expansion at its healthcare campus in Sacramento, California. The project scope of work includes construction of a new two-story, 32,000-square-foot CUP Annex Building, which will include plant operations and hospital operators support space and expansion of normal and emergency power services, including three 3MW generators. The project will also renovate the existing Campus Central Plant, including upgrades of existing chilled and hot water systems, reconfiguration of electrical infrastructure, fuel oil system capacity expansion, upgrades of industrial controls, and renovations to the existing control room and administrative spaces.

This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20251218767671/en/

Work is already underway with substantial completion anticipated in the fall of 2027. The project’s current contract value is approximately $253 million, which includes $108 million that was added to the Company’s backlog in the fourth quarter of 2025.

About Rudolph and Sletten

In the last six decades, Rudolph and Sletten has constructed thousands of projects across our five California offices, from research centers designed to cure diseases, to institutions that educate future generations of leadership. As we have grown, we have built all aspects of life science, higher education, health care, high-tech, government and everything in between. Our success is owed to our diverse, talented personnel combined with our technological expertise, honest estimates, innovative schedules and ethical business practices. Headquartered in Menlo Park, Rudolph and Sletten has regional offices in Roseville, Irvine, Los Angeles and San Diego, California.

About Tutor Perini Corporation

Tutor Perini Corporation is a leading civil, building and specialty construction company offering diversified general contracting and design-build services to private customers and public agencies throughout the world. We have provided construction services since 1894 and have established a strong reputation within our markets by executing large, complex projects on time and within budget while adhering to strict safety and quality control measures. We offer general contracting, pre-construction planning and comprehensive project management services, and have strong expertise in delivering design-bid-build, design-build, construction management, and public-private partnership (P3) projects. We often self-perform multiple project components, including earthwork, excavation, concrete forming and placement, steel erection, electrical, mechanical, plumbing, heating, ventilation and air conditioning (HVAC), and fire protection.

Rendering of the UC Davis Health Central Utility Plant Annex (source: Nacht & Lewis)