⌛Time it takes to read this article: < 1 minutesLast updated: November 28, 2021 at 10:30 PM All the Things You Are September's birthstone is sapphire. Sapphire belongs to the same ore called corundum that rubies do, and its composition consists of aluminum oxide (chemical formula: Al2O3). The most common color of sapphire is blue, but there are actually many other colors such as green, pink, orange, white, etc. Among them, I especially like sapphires with a cornflower blue (royal blue) color, which is considered the highest quality. In addition, from among the sapphires that I have collected, I have pasted the loose ones other than blue below. Among these, natural Padparadscha sapphires produced in Sri Lanka are the rarest. Pink sapphires are beautiful and cute, but when they turn red, they are called rubies rather than sapphires. (^_^;)