Ruby and sapphire are simple oxide minerals, thuộc hệ tinh thể lượng giác, the crystals are mostly hexagonal columnar with glassy luster, trong suốt đến mờ, độ cứng của 9, second only to diamond; stable chemical properties, and good toughness and Obvious pleochroism. Although ruby and sapphire have the same chemical composition, they become crystals with different […]
