The Georgia Marvel and other would be gemstones

A large crystal of sapphire from Madagascar
Photo by Rob Lavinsky 

This was found in a stream in the Blue Ridge Mountains of Georgia in 1883 and was purported to be a sapphire worth $50,000 by its finder who was assured of its authenticity by two different southern jewelers.  This fabulous find was also known as the Blue Ridge Sapphire.  The jewelers had arrived at a value for the stone based on its weight of several carats.  Eventually this stone was proved to be a hunk of rolled blue-bottle glass that took coating it onto some platinum wire to convince its finder.

This is a glaring example of how little the average person knows about gems and it seems that fallacy more then truth is known by the general public.  One of these fallacies is the belief that any stone that can be scratched by a file has to be glass.  Another is that is when a stone is hit with a hammer it’s a fake.  These practices have led to the destruction of many valuable gems.

The United States has an abundance of all types of gemstones that has never been appreciated by the average person.  In many cases these gems have been produced as a byproduct of other mining operations where many of them have slipped through the operation to be lost.  Many of the stones that were saved were discovered in places where gold was being washed with the miners being attracted to a gem because it was a shiny pebble.

Gold washing was not limited to the western US, but was also practiced in the South starting in the early 1800 with the discovery of gold in North Carolina.  It is difficult today to appreciate the size and scope of these southern gold deposits that ran through the Piedmont and Blue Ridge Mountains.  In many cases the stream banks for miles were covered with mine tailings. 

The gold wasn’t limited to placer deposits, but many mines were also producing lode gold.  Many of these mines were destroyed during the Civil War.  Recently the Haile Mine in South Carolina was found to have reserves of gold exceeding 3,000,000 ounces.  A Canadian mining company is in the process of reopening this mine.

Another of these wonders was a stone weighing more then nine ounces that was discovered near Gibsonville, North Carolina that was deemed to be a real emerald by some local expert by some “local expert.”  A microscopic examination of this stone contained numerous small sparkles of light that were thought to be tiny diamond crystals.  This stone was eventually proved to be a quartz crystal having long hail-like crystals of hessonite and actinolite that also had a series of small bubbles in a stream-like pattern filled with liquid that sparkled in the light like diamonds.

In truth the United States has produced virtually all the precious and semi-precious stones in the world.  For the most part these stones remain in the ground through lack of interest of outright ignorance.  There is also a prevalent belief that gems come from some far-off romantic place that it is difficult to reach from here.   

Gemstone Occurrences in New Jersey

A ruby crystal from Tanzania similar to those found in New Jersey.

Like many of the states of the Northeast New Jersey contains some of the best localities for finding gems in the Eastern United States.  Agate is found throughout the traprock quarries of the state as well as quartz gemstones including amethyst that occurs as cavities in the stone.  Many marine fossils are also found in the state including many fossils of shark teeth. Most of these fossils are found in the Kirkwood formation (Eocene and Miocene) in Monmouth County.

One of the most interesting stones found in the state are so-called Cape May Diamonds that in reality are waterworn quartz crystals that are found on the beaches of Cape May Point along the Delaware River in southern New Jersey.  These stones are the most abundant at Higbee and Sunset beaches in Cape May.  These stones can range in size from the finest sand to one whopper that weighed 3 pounds 14 ounces that is known as the Cape May Diamond that was found in New Castle, Delaware in 1866.

Rubies are rarely found in the white marble at the mining district in Franklin where they are found associated with the zinc mines in Franklin and Sparta.  Many of these stones are small, but are well formed.  The rubies fluoresces red, but the marble matrix doesn’t. Many minerals found on the mine dumps around the area are various minerals of zinc that also fluoresce in brilliant colors under a fluorescent light with some of them even considered gemstones.  Another mineral that is found associated with the zinc minerals is rhodonite a silicate of manganese that is often cut as cabochons.

Bloodstone or heliotrope is found in sparing amounts in the Eastern United States north from Florida with exposures in New Jersey.  This is a member of the quartz family of gemstones that is dark green in color with bright red spots of hematite.  This stone is often cut and used in inexpensive jewelry.

A polished slab of petrified wood.
Photo by Daniel Schwen

In addition to agate the traprock quarries in Passaic County also contain many zeolite minerals as well as datolite and prehnite in large quantities. In many places the traprock quarries have cavities lined with amethyst crystals.  In some areas in eastern New Jersey you can find jasper and petrified wood.

In recent years one of the most valuable gems in North America has been overlooked by collectors is the freshwater pearl found in many of the mollusks in the states many rivers.  The pearl was looked avidly for in the 19^th Century, but for a period of inactivity caused by over fishing the mollusks  caused this industry to decline.