Blue Gemstones: Here's the Buying Guide

If blue is your favourite colour and you’d like a blue gem but don’t know gem varieties except the well-known ones – sapphire, emerald, ruby – you might have a difficult time finding exactly what you want because there are more than two dozen types that I know of. 

Some of them on that list, however, don’t quite fill the bill of true, solid blue because they contain splashes, bands, e.g. Agate quartz, veining, e.g. Sodalite, or marbling effects of other colours from whatever minerals were present in their formation. An example of marbling is Lapis lazuli. 

These two gems, Sodalite and Lapis lazuli are similar in colour – a deep vivid blue – due to the high sodium content but differ because of the inclusions. Lapis, which is the better known of the two, has not just one or two added minerals but in some stones as many as 15 different minerals and thanks to the inclusion of pyrite; Lapis also has distinctive gold speckles and glitter. Those inclusions are the reason I think these stones don’t qualify as true blue stones. 

The Azurite gem also fits here because its colour is similar to that of the Lapis – that unique clear sky-blue or deep vivid blue colour, azure – but when mixed with malachite its colour is an attractive blue-green similar also to Turquoise.  But Turquoise, even though it is one of the best-known gemstones, has a noticeable touch of green to make it a non-contender for my true or solid blue gem category. 

The most valuable Turquoise, however, is sky-blue with minimal veining but again the veining makes the Turquoise ineligible for my true-blue gem category.  And, like many colours that are hard to describe because of the light source or how they are displayed on a particular coloured background, I see and prefer the more greenish colour than blue in a Turquoise gemstone.

More non-qualifiers for my True or Solid Blue Gem Category     

Because this list of blue but not true-blue gemstones is long it is impossible to name them all here so instead I’m focusing on the ones I know best and love: Iolite, Tanzanite & Tourmaline. 

The Iolite gemstone is certainly blue and similar, I think, to the colour of a blue sapphire but unlike the blue sapphire the Iolite has that amazing colour-change ability or feature like that of many other stones and when properly cut the Iolite’s colour is typically violet to purplish-blue, which is probably why I like it so much with my fondness for purple. As well, though, and in the same stone, the Iolite often displays violet-blue, yellow-gray, and light blue combinations depending on the angle it is viewed. In other words, Iolite is an absolutely amazing, if lesser well-known, stone that is suitable for jewellery because it has a hardness of 7 to 7.5 on the Mohs Scale. 

Another stunningly beautiful gem is the Tanzanite – and a definite favourite of mine – that also exhibits an intense, vivid, violet-blue colour setting it apart from all other gems available today and making it one of the most popular gemstones today. Tanzanite also pairs well with or compliments other gems, such as white topaz, diamonds, and pearls. I have seen such a necklace of pearls with Tanzanite stones, so know what I’m talking about when I say such a pairing is breath-taking. It is found in only one place in the world: the foothills of the Himalayas in Tanzania, hence its name Tanzanite. In terms of hardness, it is ranked at 6 to 7 on the Mohs scale making it slightly softer than the Iolite but still hard enough for most jewellery.  And Tanzanite has now been named the modern birthstone for December. 

There are two varieties of Blue Tourmaline: indicolite and Paraiba. Indicolite Blue Tourmaline’s colours range from light to deep-blue whereas Paraiba Tourmaline has a noticeable secondary neon-green hue. The Paraiba variety, like that of Tanzanite, was so named after the original place of discovery, the Paraiba region of Brazil. Pure or true Blue Tourmaline, however, is exceptionally rare but I include Tourmaline here because colour is really all about perception and that’s what makes it so difficult to describe, for I may see a certain colour and liken it to B because I see them as similar while others may not agree at all. 

The Paraiba Tourmaline is an example of such a conundrum or an enigma, for it is impossible to say whether it is blue or green. It is, however, the most exquisite stone I have ever seen and the most valuable variety of Tourmaline. It is also hard, registering 7 to 7.5 on the Mohs scale, and is the modern birthstone for October.

For more information about blue gemstones please contact LL Private Jewellers at 604-684-6343