Author Unknown. I was surprised at how much the element of color, or lack there of, played a role in the definition of objects. The white of the wave crests helped them to stand out greatly in the blues of the sea.
The Mohs scale of mineral hardness. It was created in 1812 by the German geologist and mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science. The method of comparing hardness by seeing which minerals can scratch others, however, is of great antiquity, having first been mentioned by Theophrastus in his treatise On Stones, c. 300 BC, followed by Pliny the Elder in his Naturalis Historia, c. 77 AD.
What NOT To Do When Etching Glass! T is back with another great tip - What NOT to Do When Etching Glass! Would you like to see a trial and error tip? I definitely have one for you today. I thought I would try glass etching and I learned a few things. I want to share a bit of wisdom with you so you do not make the mistakes I made.