silvana,sylvana berries?

hi all,
have just been to a neighbours house for the fisrt time(i want a garden like this).
they have a vast crop of large black berries(they must be inch and a half long) but they look like and pull off like raspberries(so she said).the lady told me they were silvana berries(however no offers to try one).
does anyone else grow these?i have never heard of them before let alone seen them.