Color The hue of tanzanite stone dictates its worth, just like it does with other colored gemstones. Tanzanites are generally available in blue-violet tones. However, the bluer the stone is, the more desirable and valuable it is. While the most beautiful hues are those that are deeply saturated in blue or violet, lighter pastel tones also draw a lot of attention and are more affordable. Cut Poor cutting techniques can ruin even the nicest colored gem, and tanzanite is no exception. The most ideal cuts that demonstrate the exceptional qualities of tanzanites are oval, cushion, round, and pear. So, if you are planning to get an engagement ring featuring this gem, go for any of these cuts!