Not eggs but normal exudate. It's been discussed many times over the years....here's an older thread that will clarify things for you.

When you bring the spinach in from the garden, soak it in a basin of cold water, whish it around, and then let the crystals sink to the bottom. Pull the leaves out and rinse them under running water. That will get rid of all the grit.

This won't happen all of the time; I assume that exudates are triggered by environmental conditions.

Here is a link that might be useful: calcium oxalate

Edited to eliminate duplicate post.

Here is a link that might be useful: calcium oxalate

This post was edited by rhizo_1 on Fri, Jan 30, 15 at 15:37

Thank you very much!