Customs officers pictured inspecting the meteorites.

Almost half a metric ton of meteorites declared as pyrite ore on import have been seized by authorities in the southern city of Shenzhen, China’s customs agency said on Monday.

Officers inspected the material and determined it was inconsistent with the characteristics of pyrite, the General Administration of Customs said in a statement, adding that the company involved was unable to provide relevant certification.

Pyrite, also known as fool’s gold, is an iron sulfide mineral used in the paper and jewelry industries.

A professional appraisal revealed the 470-kilogram shipment consisted of 90% iron and 8.9% nickel but lacked the sulfur content that pyrite has, said the statement, which was accompanied by a video of customs officers inspecting a number of brownish rocks.

The appraisal also found the rocks’ composition was very similar to that of meteorites, and the owner of the shipment subsequently confirmed that is exactly what they were, customs said, adding that the case was under further processing.

It was not immediately clear how the owner had come into possession of the meteorites.

China is stepping up its space exploration program and last year brought back rocks from the moon in the first lunar sample retrieval mission since the 1970s.