1, sapphire
Sapphire, which the ancient Persians thought was the reflection of sapphire that made the sky blue. It is regarded as a symbol of loyalty and respect. Sapphire is the birthstone of September. Sapphire and ruby are sister gems and both belong to corundum minerals. They are the hardest natural minerals except diamonds on the earth, and their basic chemical composition is alumina.
In addition to the starlight effect, only translucent or transparent corundum with bright colors can be called gems. Sapphire is as blue as the sky because it contains a small amount of titanium and iron.
2. Blue spinel
From the appearance, the blue spinel with the best quality is similar to some sapphires, showing bright blue or light purple blue, and its luster and transparency are also very attractive, but it is rare.
Most blue spinels tend to be smoky dark blue, even with purple tones, and their luster and transparency always have a dull and fuzzy feeling. In order to lighten the color properly, the blue spinel is often processed quite thinly. Like sapphire, its cut is usually an oval with mixed facets.
3. Cordierite
Cordierite has an attractive indigo color, which is often mistaken for sapphire, so people sometimes call it aquamarine. Cordierite is pure and colorless, and is indigo blue because it contains a small amount of iron.
A carved gem
A gem is one that has been polished and polished. Stone or mineral that can meet the requirements of jewelry. ? This precious ore is bright in color and high in hardness, and will not change under the action of atmosphere and chemicals. Can be used as instrument bearings, abrasives, decorations, etc. It also refers to precious stones.