I make two kinds of beautiful, boho sea glass jewelry. Both are handmade and one-of-a-kind. They even look similar. However, there are some important differences. First, you will notice a difference in price. 
The more expensive pieces are made with genuine sea glass that I know came from beaches. I usually know where and when the glass was collected. I choose the most jewelry-worthy of these pieces and wire wrap them in sterling silver. These become my higher end genuine sea glass jewelry. The somewhat less expensive, and often more colorful pieces, are made with sea glass that I can't verify. This glass is sold as beach glass or sea glass in modest quantities, but I believe it is actually a cultured or man-made. I still enjoy working with it because the resulting jewelry is very pretty. To keep costs down I don't wrap these in sterling.
Instead, I use a high-grade, tarnish resistant, silver or gold plated copper jewelry wire. These fun bohemian pieces of jewelry are often accented with colorful seed beads. Regardless of the materials I use to make my sea glass jewelry, it is all carefully designed and created - and every piece is unique.