An arduous yet enticing question!
A gem's beauty, its unique way of dealing with light, and its color are all the result of these properties.
It is the unique properties of each kind of gemstone that give it its beauty, color, and brilliance. Color, luminescence, and overall brilliance of gemstones have fascinated humans since the dawn of time.
No matter how long you've been interested in gemstones or how new you are to gemology, there's a lot to learn.
People are often interested in the optical properties of these stones. The optical characteristics of a gemstone are typically the most important feature, since they enable gemologists to classify them by their appearance.
Discover what makes gemstones one of Mother Nature's greatest gifts as you continue reading.
What are the Optical Properties of a Gemstone?
Essentially, optical properties relate to a stone's appearance. The way light interacts with gemstones and how different aspects are evaluated determines their specific properties. A stone's colour, lustre, and transparency can be discerned easily by simply looking at it. However, some optical properties can only be measured with the help of special tools. In laboratories, these characteristics are studied and used to classify and rate gemstones based on their dispersion, refractive index, and other characteristics.
What causes a gemstone's optical properties to mysteriously change over time? Let's examine some of the main reasons for gemstones' optical signs changing over time.
How can a Gemstone's optic sign change?
The primary cause of gemstones aging gracefully is the slow accumulation of excess moisture on their surfaces; this occurs primarily in the crevices. Water can, unfortunately, erode the stability of gemstones over time. This eventually results in hazy or foggy gemstones.
Additionally, it depends on how the gemstone is constructed internally. As an example, a gemstone may scatter light in many directions when it reflects light in a particular direction. Each beam will then be absorbed by a different color medium.
How can a gemstone cause this to happen?
There are almost no crystals in most gemstones, but instead they are made up of extremely tight chemical bonds. Crystals in this chemical structure are excited by light when it is shone on them. An excited crystal emits an electric charge, which is detectable by our eyes.
Can the sign of a gemstone change while I'm viewing it with my glasses on?
The golden rule of examining stones with your eye is to always look at them directly. Keep your glasses away when taking a look at stones.
Due to its refractive index, how can a gemstone alter its optical properties?
A gemstone's refractive index is how well the light passes through it. The higher the refractive index, the slower the light passes through. Therefore, gems with a high refractive index reflect more light than those with a low refractive index. Changing the refractive index can alter the appearance of a gemstone in many ways.
Learn why heat causes gemstones to change color
Can a gemstone change color in response to heat? Identifying the exact color of a gemstone comes down to the minerals found within it. Depending on how the minerals evolve and change, a gemstone might appear a certain color.
It is clear now why a gemstone's optic sign can change. You might be thinking, "That's great. Now I understand why my gemstone suddenly has changed color." Although a gemstone changes color when light reflects off it, it is not because the light is reflected off it.
Light reflects off the gemstone's surface, which causes it to appear iridescent. Depending on the color of the gemstone, the amount of change varies. Some changes will be more noticeable than others, so pay attention to the way the light strikes your gemstone, and you will soon understand why it looks the way it does.
But, the list does not end here. The mysteries surrounding gemstones are far from over!