Where is the 3-fields "田田田" character?

This morning I came across the Chinese character 疊(첩), which means "to pile up" or "to stack." I wanted to understand the character better by breaking it down into its component parts, but I had trouble finding one of the parts.

I found the bottom part of the character. It is 宜(의), and it means "appropriate" or "suitable." However, I could not find the top part of the character, which is three 田(전) characters stacked in a pyramid. Finally, I looked up 疊(첩) is my Chinese character dictionary and found a comment that said that the three fields (田) on top of 疊(첩) was a mistake, and that the original character was written with "three suns." That means the character on top was originally 晶(정), which means, appropriately enough, "bright."

Sometime in the past 疊 was written incorrectly, but I guess they did not find the mistake until it was too late.

疊