The Finn set the time on a short soft-tyre run late in the day, his effort of one minute 18.148 seconds enough to edge out Force India's Jules Bianchi by just 0.027secs.
Friday's session was interrupted by a red flag early on Friday afternoon when a section of kerbing broke up between turns 10 and 11, forcing a delay of around an hour as running repairs were undertaken.
Raikkonen's benchmark on Friday was not the quickest of the four-day test - that accolade instead going to Ferrari's Felipe Massa, who posted a 1min 17.879secs on Thursday.
Second place was a good effort from Bianchi, who is vying to land the second seat at Force India - the only berth still to be filled on the 2013 grid.
Bianchi might have bettered Raikkonen's time had he not had to hand over driving duties to Britain's Paul di Resta, who concentrated on longer runs in the VJM06 and set the slowest time of Friday's 12 runners with a 1:23.435.
Three-time world champion Sebastian Vettel was third in the new Red Bull RB9, with Sauber's Esteban Gutierrez amassing a useful 142 laps as he claimed fourth.
Jean-Eric Vergne was fifth for Toro Rosso, while Mercedes new boy Lewis Hamilton enjoyed a much better day at the wheel of the W04 after brake failure caused him to crash out early on day two.
Hamilton, who joined Mercedes from McLaren at the end last year, racked up the most laps of any driver on Friday - 145 - as he posted a best time some seven-tenths off Raikkonen's pace.
"Today [Friday] we managed the kind of mileage that the car is capable of and I think we have a good platform to start working from," Hamilton said.
"Now we need to understand the F1 W04 even more. Personally, I am learning something with every lap I do and every change I make to the set-up.
"Overall, I think we are probably at the level we would have hoped to be."
Sergio Perez, Hamilton's replacement at McLaren, was in close attendance in seventh, ahead of Williams' Valtteri Bottas and Ferrari test driver Pedro de la Rosa, who was restricted to just 50 laps after a gearbox problem with the new F138.
Charles Pic managed 109 laps as he finished 10th for Caterham, ahead of Marussia's Luiz Razia and Di Resta.
At the culmination of the first four test days of 2013, Sauber's new C32 racked up the highest mileage with a total of 430 laps completed, while Red Bull amassed 372 and Force India 357.
Mercedes recovered from their struggles over the opening two days to finish with 319 laps under their belts, ahead of both McLaren (298) and Ferrari (277).
Marussia racked up the lowest mileage of the test with 219 laps completed.
The second pre-season test gets under way at the Circuit de Catalunya near Barcelona on February 19.