Traditionally, rubies, emeralds, sapphires and amethysts were considered "precious" stones and the rest non-precious (diamond had precious status in India, but it was very very rare in Europe until the 18th century). Amethyst fell by the wayside in the 18th century when it was found very abundantly in Brazil. At about the same time, it became apparent that spinel and ruby are actually two distinct minerals. So, if you adopt a "traditional" point of view, you can decide that "traditionally" (red) spinel and ruby are the same and consider it precious.

Nowadays, the traditional distinction between "precious" and "semi-precious" has all but disappeared, and some of the highest values for gems are paid for "semi-precious" stones such as alexandrites. If you adopt a modern point of view, the evaluation of "precious" or not is made on a stone-by-stone basis, and nice spinels go for thousands of dollars a carat, large (over 5 carats) stones can reach ten thousand or even more for rare and sought-after colours (blue, red).

Yes, I have seen many, and when they are nice examples they are gorgeous.

Hi Pinky. I agree, As OMC and Mrs. M wrote, these days the terms "precious"and "semi-precious" are considered outdated by most in the colored stone industry. However, if you were to insist on the term, spinel is certainly a worthy gem of the title.

Spinel comes in many colors, just like the very similar gem corundum (I am sure you already know that ruby is the red version of corundum, all other colors are known as sapphire). As OMC and Mrs. M. mentioned, for centuries, red spinel and red corundum (ruby), as well as blue sapphire and blue spinel, were not understood to be distinct gemstones and there are many GORGEOUS and BIG spinel gems in royal jewels around the world (most thought to have been ruby or sapphire at one time). Hence, spinel is known as the Great Imposter.

However, that does not mean that spinel is not a fine and worthy gem in its own right – in fact, it is one of the finest.

Although they share a similar chemical composition (spinel is magnesium aluminum oxide and corundum is aluminum oxide); have closely the same refractive indexes; and are often mined from the same sources; the two gems do have distinct crystal systems as well as other differences. Visually with the naked eye, the biggest difference between spinel and corundum is that a sapphire or ruby is pleochroistic, meaning it exhibits two colors, depending upon which way you view the gem (sometimes subtle, like, in ruby you might see red and hot pink as the two colors), and spinel shows just one color... regardless of the angle from which you view it. Also, ruby and sapphire are harder than spinel (corundum is Mohs 9, spinel ranks 7.5-8 on the Mohs hardness scale). However, overall, spinel is still considered to be a very durable gem, suitable for virtually any type of jewelry.

If you couldn't tell by now, spinel is one of my very favorite gemstones, in fact, it may be my most favored of all. I have several, and I can say that the very best stones are absolutely exquisite. I am into the "water" or crystal of gemstones, and fine spinel shows gorgeous luster and crystal, almost like no other stone, IMO.

Furthermore, natural spinel is much more rare than sapphire. However, because it is not as well-known to the public (there isn't as much of it available to fashion into gemstones for the mass market), and because it has to fight-off the image of being a "cheap stone," thanks to the man-made, synthetic spinel that became so popular during the 20th century, fine spinel is still not as pricey as fine sapphire and fine ruby. In other words, although the best gem can be very expensive, spinel is still a bargain when compared to its more popular and common cousin, corundum.

I say, if you find a beautiful spinel that you love, don't be afraid to purchase it. Fine spinel is a sight to behold, especially large, clean, intense, pure-colored red or blue (beware of too much black or grey in the blue, which is easier to find in spinel than the more scarce, pure-blue color). If you find a big round, it will be even more rare and valuable (call me, lol)!
 

That is such a beautiful stone. Awesome cut and a wonderful color.

I second that motion.  Lovely raspberry color.

I haven't seen this, does anyone knows the price? i love it, so pretty!

I had a red spinel ring  once, given to me by my grandmother (it was my grandfathers), it  slipped off my 13  Year old finger. Quite a beautiful stone , I think in many cases prettier than some rubies. I am glad to see  other gems being featured as well.

Rio