Lithium Tantalate Faceted Stones, Sparkly Tantalia Loose Gems

These are lab created white lithium tantalate gems. 

Lithium tantalate (LiTaO3) is an old rarity of the gem world and rarely seen today outside of industry. It was briefly used as a diamond simulant and marketed as 'tantalia', but was never very successful- tantalate is much brighter and more dispersive than a diamond,so there was an obvious difference when cut. Faceted lithium tantalate gems give off brilliant rainbows of color, so it's an amazing gem in its own right instead of just trying to imitate diamonds.

Note that LiTAO3's hardness is just under 6, which makes it harder than some other classic diamond simulants (like lithium niobate and strontium titanate) but still soft for a gem, a little softer than tanzanite. It is not a good stone for rings but will work well in lower-wear jewelry like pendants or earrings.

Today lithium tantalate is only grown for scientific and industrial usage--its very unusual optical and electrical properties like piezoelectricity and pyroelectricity make it an incredible material for things like fiber optic networks. There has even been a fusion reactor designed around it!