A picture of the leaf would be helpful. Next, some Echeveria leaves just are difficult to produce new plants or don't for whatever reason. I have had some carnuculated leaves that have great roots but in more than 4 months have not sent up new growth, while others have. Some have been outside in sunlight for the past 2 months and still nothing!

Thanks, bikerdoc.
I've attached a photo of the leaf I'm trying to propagate below...any thoughts as to the species?

Would you recommend putting it outside now that there are roots, or should I keep it inside under the light?

Thanks.
-Nick

Just a guess but it looks like it could be Echeveria affinis 'Black Prince', bcause it does have some color on its distal end, which usually will grow a new plant rather easily. Possibly more sun might get it going.

Thanks for the help!