Why Do Diamonds Shine?

Diamonds are the beautiful, shiny and extensively hard mineral found in our nature. The word diamond has been derived from a Greek origin with words “adamas” meaning invincible and indestructible which is property. It has various interesting properties such as hardness, high melting point, unaffected against heat, transparent, and most of all their beautiful shiny magnificence, due to this lustrous shine it is used extensively in jewelry and decoration industry.

Scientifically diamonds are a complex version of carbon only, with one carbon atom attached to four other carbon atoms and the network follows on, due to this unique structure it becomes hard and because of this tightly knit bond, it is unbreakable. These are billions of years old, found in coal mines when the coal is under high pressure it beautifies to grant such a precious stone. It is considered the hardest known mineral found in nature. Due to its low availability in nature, it is highly expensive in the market, after all, the shorter the supply the higher goes the demand. Diamonds are also used in industrial processes like cutting and drilling. AN interesting fact is that a diamond can only be cut by another diamond as no other material is strong enough to pierce through it, but it is most famous for decoration and jewelry because of its marvelous shine and beauty.

The shine of a diamond is what gives the diamond its uniqueness, every diamond has its own unique shine, but we have never wondered that why do diamonds shine?? The answer to this can be explained by two scientific phenomena which are: total internal reflection and dispersion.

Total internal reflection is a scientific concept of physics and is related to the reflection and refraction themes the name suggests.

For a small recall, Reflection is when a ray of light hits a surface and bounces back the whole inclining at angles whereas, Refraction is the phenomenon where a ray of light passes the interface and because of change of density of the matter/ surface bends. These all are broadly categorized as an optical phenomenon of science.
It is observed when light is travelling from a denser medium to a rarer medium, if the incident angle of light on the interface of the two given media is greater than the critical angle i.e. the angle which the incident light would reflect and star gazing through the interface then the light ray would get reflected in the medium it is coming from.in simpler language when the light will move from a denser medium to a rarer medium for example from glass to air and hits the point (critical point) where the light starts getting reflected on the surface instead of refracting, enabling to appear as shiny. In case of diamonds, due to its highest refractive index, it has the minimum critical angle of 25 degree thus when light enters a diamond it strikes on its surfaces many times which produces a sparkle which we see as a shine. Thus we can say that diamond’s shine is not shining but reflection.

Also different types of diamonds with different structures, mass, size, shape, and color can exhibit the shine in their own unique ways. Such as the raw diamonds found in coal mines they have comparatively very less shine as to those which are finely cut, and hence said the difference amongst polished and unpolished diamonds. Raw diamond possesses a greyish shine whereas when these diamonds are cut to make jewelry and ornaments they are done in such order that the light gets reflected in it many times appearing as the diamond has trapped the light in itself which in result leads to very bright shine and amazing sparkles.

Dispersion is another phenomenon in which white light splits into its seven components of light namely; violet, indigo, blue, green, yellow, orange and red, when passed through a glass prism and alike structures. In case of diamonds which can be considered as small prisms in this situation, reflects, when the white light after many total internal reflections finally emerges out of the diamond it gets split into its seven components due to dispersion as a result viewer is able to see a wonderful display of colored light from the diamond. This display is known as the diamond fire. Some diamonds can only emit a particular color when viewed from a particular angle and it appears that the diamond shine is of that color, these flashes of color are known as the life of the stone. About one-third of diamonds glow under ultraviolet light and gives a characteristic blue color which can be noticeable under black light or strong sunlight.

Thus we can say that the diamonds are not luminous objects and do not emit light on their own but simply reflects the light and will not shine in the dark. We need a light source for a diamond to show their shine.
To get the desired shine and sparkle, raw diamonds are cut in fine shapes and then polished to enhance the shining effect by reflecting more amount of light. But the shine of diamond is not invincible it can become dull over a period of time and to avoid that, a tip is that it is important to clean diamonds with lotions and soak in warm water to keep the shine at its best.

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