Black Glass or, sometimes referred to as “Pirate Glass,” is a very old and rare type of glass used in the 1600s to the 1800s mostly for bottles. The oldest black glass is amber or olive green and sometimes contains bubbles. There is also more recent glass from the late 1800s to the early 1900s that appears black, but under strong light can show a variety of bright colors. Those are generally found on the Durham Coast of England on beaches like the famous Seaham Beach.