The phrase "although not common" is correct and usable in written English.
It can be used to introduce a contrast or exception to a statement, indicating that something is rare or infrequent.
Example: "This type of behavior, although not common, can sometimes be observed in certain situations."
Alternatives: "even if rare" or "despite being uncommon".
Although not common in Canada, they have been a judicial fact of life for some time.
Although not common, taking ownership of the home you are leasing can be a choice for renters, not just those who are former presidents.
Although not common, scientists warn that an outbreak like this should be expected somewhere in Europe within the next 50 years.
Although not common, examples exist in the record of historical imagery of gullies that underwent infilling by aeolian sediment in past decades and evidently were effectively annealed.
CONCLUSIONS: Although not common, neuromuscular injuries during laparoscopy do contribute to morbidity.
Although not common, 3D methods can fill missing parts of a frame by using information from several other frames [48].
This is not the first demolished stadium site to be restored for baseball use by a city's residents, although it not common.
Although still not common in practise, reasoning based on reference terminologies and ontologies is expected to become one of the major benefits of terminology bindings of the clinical content models.
Although it is not common for editorial boards to include experts with little experience in journalism, it is hardly unheard of.
Since owners must enter into individual contracts with the vendors, some have arranged for a cut of the advertising revenue, although this is not common across the industry.
The process is also reported to reduce aflatoxin levels by up to 90%, although it's not common outside of Latin American cultures.
