What is Black Glass?
Black glass (sea glass) is very old glass generally from bottles made in the late 1500s to the 1880s. It is called “black” glass because sunlight barely penetrates through it, making it look black. It’s also called “Pirate Glass” and “Secret Glass.” Even though it appears black, if you hold it up to a strong light source (like the flashlight of your mobile phone), you’ll usually find that it has a deep olive color. That was the traditional color that bottles were made of at the time. But once in a while, you’ll find a rare piece of a different color. Some came from insulators and some from a combination of colors dumped by the factories at the end of the day.
Distinguishing Black Glass from Pebbles on Seaham Beach
Black sea glass is very rounded and smooth after being tossed in the ocean for 400 years, looking very much like pebbles. For some reason I developed a knack for spotting them amongst the rocks. My cousin always finds the bright pretty pieces, and I seemed to be drawn to the black ones.
The glass has a slightly different finish than the stones, so I was able to easily spot them. Hold up both a piece of glass and a stone and you’ll see the difference in the finish. I ended up finding about 3 pounds of black glass on Seaham Beach.
Using a Light Source at the Beach
I sometimes couldn’t even see the color when holding it up to the sky, so I always brought my mobile phone with me, to use the flashlight. Once I almost missed one of the finest pieces I ever found because it was so bright outside. The dark blue tip swirls down to a deep purple. I show it on my YouTube video. But the sun was so bright outside, it looked mostly like a rock, and I almost missed the blue tip. Check them while you’re on the beach so you can avoid carrying pounds of black rocks back to your place, then have to bring the rocks back to the beach. Yep, I’ve done that, so now I check them all while I’m still at the beach.
Black Glass in Spain
We also found a good bit on the island of Mallorca in Spain. This is the first place that I ever found some. We were wading in the water (about waist deep) and it was so clear, that we could see dark specs in the sand below. Picking up the pieces with our toes, we noticed that they were a deep olive green, and knew then that we had found black glass! Each of us found about 8 -10 pieces in that cove. Below are two maps showing where the cove is in proximity to Palma.