Does anyone know this brand?

So this necklace was my great grandmother’s, and I’m wondering what the brand is. On the back there is some sort of logo and text. The text is basically rubbed off by now. It’s a Magen David (Jewish star) pendant, the logo looks like two overlapping c’s and one has a dot in the middle. She got it in Israel and I believe that it has genuine Eilat stone in it. If anyone can ID the brand, it would be great.