A poor man's diamond is the colloquial nickname that refers to several different gemstones, which resemble diamonds or cost much less than real diamonds, while offering a similar and brilliant aesthetic.
The phrase "poor man's diamond" refers to gemstones which include.
Aquamarine, which is a pale blue, March birthstone and is a durable, semi-precious beryl crystal that provides a clear and icy look for a fraction of the cost of a traditional diamond.
Natural zircon, in gemology, is sometimes referred to by the nickname "a poor man's diamond" because it's high refractive index creates intense fire and sparkle, which makes it one of the oldest natural diamond simulants.
Herkimer Diamonds, which are exceptionally clear, double terminated quartz crystals found primarily in Herkimer County, New York.
Collectors of the Herkimer Diamond affectionally call them the poor man's diamond because they grow naturally with beautiful, raw diamond like facets.
And cubic zirconia, which is often just called a diamond simulant, CZ or cubic zirconia is regularly referred to as an affordable alternative for a "lookalike" diamond.
It's also visually convincing when new, although it also lacks the durability and scratch resistance of a true diamond.