LONDON (AP) — Britain’s Tate gallery has bought a work by Chinese artist Ai Weiwei made up of eight million porcelain sunflower seeds — a portion of the 100 million he brought to London in 2010.

Tate said Monday that it had purchased “Sunflower Seeds 2010” — 10 cubic meters (13 cubic yards) of seeds, hand-crafted by Chinese artisans, which can be displayed either as a conical pile or as a square or rectangular bed.

The gallery did not disclose the price. Last year Sotheby’s auction house sold a 100 kilogram (220 pound) bag of the seeds for 350,000 pounds ($550,000).

In 2010, Ai covered the floor of a 1,000 sq. meter (10,000 sq. foot) hall at London’s Tate Modern with almost 100 million of the seeds. Visitors were initially invited to walk or lie on them, but after a few days the ceramic dust was judged a health hazard and the exhibit was cordoned off.

It still proved a hugely popular show. The gallery said the seeds, a common Chinese street snack, represented friendship and compassion, raised questions of individualism and evoked the enforced conformity of the Cultural Revolution, when propaganda posters depicted Chairman Mao as the sun and Chinese people as sunflowers turning toward him.

The bearded and burly Ai, 54, has exhibited widely in Europe and the United States and last year was named the world’s most powerful artist by Britain’s Art Review magazine.

He helped design the futuristic Bird’s Nest stadium for the 2008 Beijing Olympics, but later soured on the event.

His social activism has brought him into conflict with the Beijing authorities. In 2011 he was detained for almost three months during a wider crackdown on dissent, and has since been investigated for tax evasion.