Snow (Gem) Leopard Geckos
A Gem Snow leopard gecko has black bands and a white body just like a Mack or Tug Snow, though its bands turn into spots during growth. Because you cannot tell the three lines apart by eye, you should ask about parentage before you put one into an existing snow project.
About the Snow (Gem) gene
The Gem Snow morph removes the yellow from a hatchling's leopard gecko pattern and leaves white with black bands. These bands turn into speckling as the animal grows. It is a snow line in the hobby like Tug Snow and Mack Snow. It is kept for a high-contrast look that is clean. It is a separate line instead of a relabelled Mack Snow.
Appearance
A Gem Snow starts with black bands on a white body, just like a wild-type gecko but without the yellow. This high-contrast look with less yellow stays until adulthood as the bands break into speckled black markings on the tail and back. You should look for the lack of yellow instead of a specific marking. Because a Gem Snow, a Mack Snow and a Tug Snow all end up with the same white-and-black adult pattern, appearance alone cannot tell the three lines apart. Decisions on pairing should rest on parentage records.
Genetics
One copy of Gem Snow is enough to show the trait because it is dominant. The name Super Snow (Gem) for the two-copy form is not confirmed. To date, breeding two Gem Snows has not produced a distinct super. Instead, the name is used for a Gem Snow crossed with a Mack Snow or a Tug Snow, which is sold as a Super Snow by that convention. It is unsettled whether Gem Snow shares a locus with Mack and Tug Snow, which would make that cross a true super. Morphpedia records no complex for Gem Snow, but the question of alleles stays open because pairings with Mack Snow produce super-looking offspring. Snow (Mack), Snow (Tug), Snow (LBS) and Snow (Albey) are separate lines, not this gene under another name. Breeding records rather than looks tell these grown lines apart. Jim Holler of Reptilian Gems first bred Gem Snow.