A copy of the image on the Royal Collection site proves that the jewels in the print above could not be the turquoise parure, designed by Prince Albert, which QV later gave to Princess Christian, as the print was published on 24 May 1843.
In her diary QV noted that her newly acquired turquoises were supplemented by some she already had, and a detail of the tiara depicted in the print does suggest a darker coloured stone, so the tiara depicted in the 1843 image of Queen Victoria might have had turquoises.
but I would still not be inclined to conclude that the necklace had turquoises. I still feel the necklace is more likely to have opals.