The 'Twilight' heartthrob gave the gift to his co-star and girlfriend with a personalized inscription and photos of them together inside.
According to the US edition of Star magazine, the Latin inscription reads: "Even if you can't see me, my love for you is always there."
Kristen is reportedly overwhelmed by the gift and it Robert's gesture has strengthened her love for him further.
A source said: "She was really touched-it was so incredibly sweet.
"She's been in tears, saying she can't face being away from Rob for too long and that it physically hurts her."
Kristen, 21, is a lover of vintage jewellery, and one Halloween Robert, 25, presented her with a vintage gold ring with a red heart.
The couple's hectic work schedules sometimes keep them apart for long periods, but in April Robert was said to be preparing a lavish gift for his girlfriend, but that only makes them more romantic when they do see each other.
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