Dagmara Przybysz, 16, was pronounced dead at Pool Academy, near Redruth, on Tuesday 17 May.
The inquest was told a post-mortem examination had been carried out but the cause of death was not yet available because the toxicology reports were outstanding.
The hearing, in Truro, was adjourned to enable the reports to be compiled.
The body of the teenager, who was originally from Poland, was formally identified at the Royal Cornwall Hospital by her father, Jedrzey Przybysz, on the day she was found, the inquest heard.
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The academy's principal, Zelma Hill, previously said the teenager was a "beautiful, bright and creative 16-year-old student with a very promising future ahead of her".
Tributes have also been paid to her on the Pool Academy school Facebook page.
Police have not been treating the death as suspicious.
An inquest into the death of a teenager whose body was found at her school in Cornwall has been opened and adjourned.