I just tried two black teas this week that would fit the OPs description, and wrote up my tasting notes here
Ruby Black Tea, Winter Harvest 2009, Yuchich Township, Nantou County, Taiwan, from Norbu
'Buddha's Hand' Fo Shou Hon Cha by Imperial Teas of Lincoln
And the summary (see the link above for the photos and full notes)
"They looked nice, smelled good, and the first one I tried, the Black Ruby, was delicious, so I decided to try a formal tasting with the two of them. And they were both quite nice. After a first very timid set of dilute infusions, I let them go more normally, and got a nicer fruitier tea from both, although I think the fruitiness was sharper and more interesting from the Ruby Black. But when I spent a few minutes letting the teas cool as I was writing up my notes, they did start to get a bit bitter--an important lesson here, I think, is brew and drink before that can happen."