Spinel is the magnesium aluminum member of the larger spinel group of minerals. Its hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, blue, green, yellow, brown, or black.
Rose Gold gets its rosy tint by mixing copper with gold. The ratio of gold to copper is usually 3:1, but varying percentages can be used as well, the intensity of the color differs according to the ratio of gold and copper. Jewelry with rose gold plating gives off a quality of elegance and femininity.