I recently read about different phases of ice on Wikipedia. But I can't find any pictures of the different ice phases. Do they all look alike visually? If you weren't able to measure the pressure and temperature, would you be able to tell one phase from another in any way?
I don't know of any experimental results on the optical properties of ice at high pressures. I'm sure they must exist, but I couldn't find any relevent publications.
However there has been lots of work on theoretical calculations of the optical properties. See for example Ab initio investigation of optical properties of high-pressure phases of ice and Blueshifting the Onset of Optical UV Absorption for Water under Pressure. The results of these calculations are that the optical properties do not change in the optical spectrum, though you get big changes in the UV spectra.
So assuming you trust the calculations the answer is that all the different phases of ice look the same to the eye. All the phases are clear, and the refractive index doesn't change (much) so you wouldn't see a difference in the sparkle.
Yes, they would all look alike, atleast at the scale we see!
There is a table given on the page you redirect to, it tells that the different ice phases are different in terms of being amorphous or crystalline or having different types of unit cells.
Although these unit cells are vastly different and produce different shapes at molecular level, they do not have any significant visual differences to be seen by us.
Look at these different elements of different structure
Common Sal(NaCl), Cubic Structure
Graphite, Hexagonal Structure
Calcite, Rhombohedral/Trigonal Structure
Monoclinic Sulphur, Monoclinic Structure
Titanium Dioxide, Tetragonal Structure
Apart from the colors none of these crystals can be differentiated from one another, Just imagine them in a single transparent like color like that of ice.
It is clearly evident that they should all look the same!
PS: I also did not found any special image of different phase of ice, perhaps because they all look same!