The phrase "although virtually" is correct and usable in written English.
It can be used to introduce a contrast or exception, often indicating that something is nearly or almost the case, but not entirely so.
Example: "The project was a success, although virtually no one expected it to be completed on time."
Alternatives: "even though almost" or "despite being nearly".
Although virtually none of these ladies work, they embody the ruthless competitive spirit of entrepreneurial capitalism.
Although virtually intact and absolutely genuine, it has all the deadness of a latter-day reproduction.
Ships may be either publicly or privately owned, although virtually all nations subsidize their merchant marine.
Although virtually unknown to modern readers, the Battle of Wildcat Mountain was a very important part of the early war.
Houses varied considerably in size and shape, although virtually all had palm-thatched roofs and walls of thatch or adobe.
Although virtually free of antique motifs, Pacher's painting demonstrates the growing fascination of Italian Renaissance art for northern artists.
Although virtually unknown to consumers, the information has long been considered the most potent weapon in pharmaceutical sales — computerized dossiers showing which physicians are prescribing what drugs.
But Hill, although virtually abandoned by the senators who had forced on her the task of bringing down a Supreme Court nominee, stood her ground.
At the time, although virtually surrounded by water, Logan had no water-rescue plan their equipment sat useless at the end of the runway overlooking the harbor.
At the time, although virtually surrounded by water, Logan had no water-rescue plan — their equipment sat useless at the end of the runway overlooking the harbor.
Iraq is a focus of attention as lawmakers have scheduled five weeks to finish legislative business before departing to campaign for the Nov. 5 elections, although virtually no one expects that Oct. 4 deadline to be met.
