NANJING, June 16 -- Scientists at a Chinese observatory on Tuesday said they have discovered a macronova from gamma-ray bursts, which could help explain how gold and silver originated.

Physicists have long puzzled over how elements heavier than iron such as gold and silver originated, as stars themselves cannot generate such elements.

Analyzing the data of GRB060614 gamma burst, researchers at the Purple Mountain Observatory, Israeli Hebrew University and Italian INAF/Brera Astronomical Observatory found a macronova, which has been proposed as the source of heavy elements.

It is the second macronova discovery and will give scientists a new opportunity to explore the origins of gold and silver, the Chinese team said.

The discovery also sought to explain a glitch in the categorization of gamma-ray bursts, the Chinese team said.

Gamma-ray bursts have been categorized as short and long mainly based on whether their duration is longer than two seconds. However, two gamma-ray bursts that should have been long bursts exhibited features of short bursts, according to a discovery in 2006. The GRB060614 gamma burst is one of them.

The discovery of macronova in GRB060614 suggested the gamma-ray burst came from the merger of a neutron star and a stellar-mass black hole, where short gamma-ray bursts always originated, the Chinese team said.