Here is another clue, the hexagon pattern which is a common theme in ME.
Also, as [kotaku.com] (Blackout62) else pointed out earlier, the two numbers that Bioware have alluded to were: 55.845 and -128.5°F. The mass of iron and the coldest temperature on earth.
Mass of iron & coldest temperature on earth
Mass of FE (iron) & CT on earth
Mass FE CT on earth
Mass Effect on Earth!