The Culanda Stone, Glowing is a luxury furnisher item. The Auridon achievement items you saw are the Tanzelwil Culanda Stone and the Veiled Crystal. The light of those is quite small (which can be a good thing, if you're trying to find a non-overpowering yellow crystal). They also have an 'off' setting which can be toggled, while the Culanda Stone, Glowing doesn't.
That one can light large rooms and entire smaller houses all by itself, and has very bright very yellow illumination. (The same is true for the Varla version, except that one is blue - you can mix the two for a slightly more neutral sharp light). Here's an image from Stone Eagle Aerie to compare. So as you can see, your choice will depend on what you'd like to light up - the Culanda stone in smaller rooms is eye-abusingly bright.