Yesterday I was in a mall and I saw an amazing little Calamondin tree for sale. It was really beautiful, it had really DARK leaves and they were also VERY glossy. I wish I would've been able to take a picture. The tree was really small, about 9" tall, but had plenty of fruit (and leaves of course). I mean, my Calamondin tree is also covered with leaves that grew on it while it was still IN THE nursery, but they're not even close to being so dark and glossy. My tree is from Holland, and the tree I saw in a mall was probably from Portugal.
So my question is: is there any chemical to make the leaves so glossy and dark, or is there some trick for that? I'd really like to know!
We have some speacial cloths to make the leaves glossier, it says "it cleans, makes leaves glossy and fertilizes" What do you think?

Dark green leaves are from health well fertilized leaves with no mineral deficiencies, but they are also older than a few months. Citrus leaves are always lighter green when they first form and get darker with age.

Nitrogen gives leaves of a good green

CF4 many of the common leaf shines sold at retail garden centers do plug the stomata, but for how long depends on the volatility. While there are stomata on the surface of a citrus leaf, the vast majority of stomata are located on the underside of the leaf. Therefore if you carefully spray only the upper portion of the leaf blade, almost no stomata on the underside will be effected. Horticultural oils like UltraFine have a high rate of volatility, and remain on the leaf blade for only relatively short period. - Millet (1,025-)