The phrase "an irreplaceable source of" is correct and usable in written English.
It can be used to describe something that is essential and cannot be substituted or replaced.
Example: "The library serves as an irreplaceable source of knowledge for the community."
Alternatives: "a vital source of" or "an essential source of".
Dr. Floersheimer, who received an honorary doctorate in humanities from Yeshiva University, was an irreplaceable source of guidance, inspiration, direction and insight.
Although manufacturing now accounts for only about a seventh of G.D.P., it remains the sector most attuned to the economic cycle; it is an irreplaceable source of innovation and exports; and it has great symbolic importance.
I spoke to a young man called Max Brooks* – imprisoned for offences including graffiti, drug possession, robbery and unlawful wounding – who says his probation officers have been an irreplaceable source of support for him.
The 190 countries -- including the DRC -- that have pledged to adhere to the World Heritage Conventions have an obligation to speak up now and enforce the commitment made 35 years ago to protect Virunga, an "irreplaceable source of life and inspiration... that belongs to all the peoples of the world".
Second, targeted studies dealing with infectious pathogens generally require an effective collaboration with hunters, as the carcasses of hunted animals are an irreplaceable source of samples.
The list also includes Hydro Quebec, the Canadian company whose hydroelectric dams are a "critical, irreplaceable source of power to portions of Northeast U.S.," as the cable says.
But it could, in a broad way, be interpreted as siding with Husserl, Ludwig and Searle in thinking of consciousness as the irreplaceable source of intentionality and meaning.
In the traditional view, religious communities are not only real but irreplaceable sources of meaning and belonging.
Natural products from higher fungi origin are irreplaceable sources of architecturally distinct scaffolds for drug discovery [1, 2].
There's a constant hysteria in the land about threats to the Constitution, to religion, to strategic territory with irreplaceable sources of water or raw materials sold to secret American or Israeli companies.
Compressed air is an irreplaceable energy source for some manufacturing processes, and is also common in applications even when there are alternatives.
