http://www.ajsgems.com/GemLibrary/Sapphire.shtml
Sapphire and Ruby are both corundum (the basic chemical formula is Al
2O
3 (alumina) is the same for both ruby and sapphire.) Sapphires are corundum of all colors except red. Red corundum is called ruby. Although pure corundum is colorless, blue sapphire results from a combination of titanium and iron oxides. The name sapphire comes from the Greek word "sapphirus" for blue but sapphires come in many colors including pink, yellow, orange, green black, purple, violet, light blue, and the rare orange-pink Padparadscha" sapphire. Padparadscha comes from the Sinahalese word meaning "lotus color". Sapphires other than blue ones are usually called "natural fancy-color sapphire". Red hues result from traces of chromium. The greater the concentration of oxides, the deeper the color.
Sapphire's enchanting colors are just one reason for this gemstone's popularity. It's also extremely durable, having a hardness of 9 on the Mohs scale. Sapphire has a specific gravity of 4.00, a refractive index of 1.76 - 1.78, and birefringence of 0.008.
http://www.ajsgems.com/GemLibrary/Ruby.shtml
Fine Rubies, especially Burmese rubies are among the rarest and most expensive gemstones in the world. Prized for their beauty, durability, and rarity, it is the quality of the color which most determines the value of the stones. The ideal Ruby color is that of a red traffic light, a highly fluorescent red of high intensity. Demand for gem quality Ruby has always been strong with mining records from Burma dating back almost 500 years.
The word ruby comes from the Latin word for red -- ruber. They are a form of corundum which is colorless in its pure state. The red color is produced by small traces of chromium. Traces of iron make the color more brown. Although Burmese, African, Thai and Cambodian rubies have the same chemical and physical properties, they differ noticeably in color and hue.
Burmese rubies are the best rubies in the world and the most sought after. Burma ruby is the rubies that we specialize in. Burma ruby displays a true red to pinkish red color in most kinds of light. African, Thai and Cambodian rubies are usually much darker and browner in color and similar to garnet. Many rubies on the market have been heated to enhance the color. This is a generally accepted practice in the gem trade and gem labs classify them as natural rubies.
Rubies and Sapphires which are both members of the corundum family have the same hexagonal crystallographic structure. It is the presence of trace elements like chromium, iron, vanadium and titanium which are responsible for the wide range of colors in which the mineral occurs. The red color in Rubies is primarily a result of the presence of chromium. Red corundum is known as Ruby and any other color is called a sapphire. In practice however, the determination is not always so straight forward because there are no internationally accepted standards for the color of a ruby. Gemologists could describe the same stone as a pinkish red ruby or a pinkish red sapphire and borderline cases are not uncommon.
Just thought you ladies should know, but something tells me the PF sisters do their homework well in advance and are well-informed.
Yes, and any suitor should be expected to know the lady's preference.
Of course, I'm not sure how much he paid for it, just what it would cost at the time I found out.
