Hello!
To me it looks like Compacta, which should grow a little shorter than regular trifaciata and laurenti.....dark centers contrast nicely with the gold edges. I sometimes see this on ebay and such as "Black Gold", which is not a valid name. It could also be 'Slipped Stripes'/'Lilian True'.....but I don't see much striping.
It still looks young, maybe by next year we can say for sure!!

I've had it for a few months now, it's doubled in size but hasn't grown taller.
Thanks for the help.
Tally HO!

I feel that it may be "Lillian True" The leaves are straight and not twisting. I am talking about the plant in the front in the picture. Norma

Thanks Norma! Both of these plants are opposite ends of the same rhizome. I am fascinated that there is so much difference between the two, you would never think they were the same plant.
Tally HO!