Q: I've noticed that for some beads such as natural pearls and malachite, it's recommended that they be strung on silk or similar with knots between beads to protect them, while other beads such as amethyst and crystals can be strung touching each other on something like Accu-Flex® beading wire. Is there an easy way to determine which beads should be strung and knotted on silk, and which ones will be okay strung on metal?