Hi Mike thanks for writing in. Do you mean Van Dell Costume Jewelry? Van Dell manufactured gold plated jewelry, (RI - 1943) founded the same year that Hitler declared "Total War" (january 13th). There was a demand for this type of costume jewelry, that had the look of fine jewelry , but was nowhere near as expensive.
The company used Rhinestones, that simulated diamonds. These stones have the same exterior features of diamonds but that's where the similarity ends with simulated stones. . They also used cultured and imitation pearls.
So it is not surprising your piece looks amazing. Often Van Dell pieces resemble fine 20th century jewelry. Authentic Van Dell jewelry enjoys high book prices.