fuckyeahmineralogy: A naturally rhombic specimen of calcite (CaCO3). Well-formed calcite like this is often referred to as optical calcite; being rhombic instead of a perfect cube, the calcite can cause an image directly underneath it to appear twice.

fuckyeahmineralogy: A naturally rhombic specimen of calcite (CaCO3). Well-formed calcite like this is often referred to as optical calcite; being rhombic instead of a perfect cube, the calcite can cause an image directly underneath it to appear twice.

tags: So many OTPs, queue,

from: https://eikuuhyo.tumblr.com/post/116371374362