Snowflakes often have a six-pointed structure.

six-pointed 是由数词 six（六）和名词 point（点、尖端）加上后缀 -ed 组成的复合形容词。pointed 表示"尖的、有尖端的"，six-pointed 合起来表示"有六个尖端的"，即"六角形的"。