Broken glass, ceramics and old hair combs.

It may sound like pieces of garbage, but these items are giving historians rare glimpses into one of Australia's oldest colonial sites.

Female patients sit outside the Parramatta Hospital for the Insane in 1888. ( Supplied: Urbangrowth )

For the past two months archaeologists have been digging in North Parramatta, the site of former institutional care facilities.

In the early 19th century female convicts were housed in the female factory.

The site was then expanded to include a mental asylum and an orphanage.

Senior archaeologist Rhian Jones said it was one of the first times the area had been explored in this way.

"We've got toothbrushes, hair combs, beads, bits of jewellery, so we're not sure if they're the matron or the people who are officially allowed to wear those kinds of decorative items or whether the girls from the industrial school period have access to them," she said.

"Hopefully some of the items relate to some of the orphans."

Ms Jones hopes to uncover information about the lives of girls and women who lived in the institutions.

Indigenous workers digging in the archaeological pit in North Parramatta. ( ABC News: Jackson Vernon )

"There's a lot of historical records about the store room and what is the government providing, and types of cooking implements and clothes the orphans, and then later the girls, from the Industrial School were provided with," she said.

"But that doesn't give that unofficial record of how they're spending their time or any of the other activities, the unofficial activities that they're doing in these spaces."

Evidence of coexistence

Also among the discoveries are a number of small pieces of glass.

Archaeologist Jillian Comber said it possibly dated back to 1788 and was evidence of the relationship between Aboriginal people and European settlers.

She said the Aboriginal people adapted the glass to be used for cutting or carving.

Archaeologists say this glass shows evidence of coexistence between Aboriginal people and European settlers. ( ABC News: Jackson Vernon )

"The glass is really important because we don't have a great deal of evidence of that coexistence between Aboriginal and non-Aboriginal people," she said.

"It's a very significant find for Aboriginal people for the history of Australia as well.

"The glass shows that Aboriginal people were here and were utilising new materials, changing their technology, their technique of making artefacts, it shows that ability to adapt to circumstances."

Descendants of the local Aboriginal tribe have been part of the discovery team.

Jamie Eastwood, from the Darug Tribe, said it helped dispel myths about Aboriginal people.

"There's the stereotypical idea that we're stuck in the Ice Age and never change, but we had to adapt to many things, between colonisation and adapting and adapting all the time," he said.

The archaeological dig is part of an $18-million project funded by UrbanGrowth New South Wales to repair the heritage buildings in North Parramatta.