Two men have been charged after police found opals valued at more than $4 million at a hinterland property on Queensland's Gold Coast.

Police uncovered the gems on their second day searching a Guanaba residence.

They found stolen cars and other property at the address earlier this week.

Detective Superintendent Dave Hutchinson says it is an Aladdin's Cave that has yielded cash, an excavator, two trucks, a speedboat, caravan, power tools, televisions, car parts and the opals.

"The vast majority of them are still uncut opals," he said.

"I believe there's one rock there that weighs about 500 kilograms and then there's an assortment of other rocks with opals in them and then there's a small amount of polished opals."

Detective Superintendent Hutchinson says police will finalise their search today and that they could know the rightful owner of the opals.

"We haven't identified positively yet where the opals came from, but we have an idea and if we are right they were stolen about 12 months ago," he said.

"Obviously nothing has actually occurred with them in that 12 months.

"We are regarding with the complainant in that regard to try to establish whether or not they are the one."

Detective Superintendent Hutchinson says one man has been charged with drug offences and the second man has been detained over the suspected stolen property.

"No connection has been identified with any bikies or bikie associate from an organised crime perspective - that's still to be determined," he said.

"Obviously this is quite a big operation that's been running for quite some time, so there may be an element to this particular group.

"That's something that will be determined hopefully over the next few days."