Why do gemstones have color

However, the rich blue color is the most valuable and popular stone. Rubies are also found in different shades of red, while the color known, as "pigeon's blood" is the darkest and richest red available, which is very powerful. This deep red ruby is mined only in Myanmar. When precious stones are found in mines, they do not look as attractive as they should be. Stones are usually polished, carved and cut into different shapes and sizes for it to acquire its beauty.

According to the polish of the stone, the value increases. It is a common notion that the deeper and richer the color of the stone, the more precious and valuable it is. For instance, bright white pearls, green garnets, royal purple amethysts, yellow topaz, deep red corals are the most precious and valuable gem stones existing.

A lighter colored gemstone, like a light green garnet isn't as precious as a parrot green garnet. It is very difficult to obtain the richest color of a stone, as they are very rare. Thus most of the people settle with lighter colors, as they are easily available and very affordable. These days, people prefer a lighter garnet, or a lighter purple amethyst, as it is next to impossible to afford or find the "perfect" green or purple.

Different colours of light have different wavelengths, so the exact wavelengths that are absorbed will affect the colour that the object appears. For example, an object that absorbs all wavelengths of visible light that pass through it, but does not absorb red light, will appear red. Why does this absorption of light occur in the first place? This is dependent on the elements present in the structure of the gemstone. Conversely, the transition metals the large group of metals in the centre of the Periodic Table are capable of absorbing coloured light.

Transition metals have this capability because they have electrons in d orbitals. Orbitals are essentially regions of space around an atom in which electrons can be found; they can have different shapes and energy levels. The d orbitals in transition elements are partially filled, and this mean the unpaired electrons therein are capable of absorbing visible light in order to promote the electrons to a higher energy level.

When they do this, the wavelength of light they absorb is removed from the light completely. Different transition metals are capable of absorbing different wavelengths of visible light, thus giving the wide range of colours seen in gemstones. The transition metals may be part of the chemical formula of the mineral, or they may be present in the mineral as impurities. Shop Gemstone Carvings. Shop Fancy Gemstones. Shop Star Gemstones. Shop Unheated Sapphire. Aquamarine - Colored by Iron.

Reproduction text or graphics without the express written consent of GemSelect. Gemstone Information Sign up for our Newsletter. Shipping Payment Seller Trust. Click for Details. Add to Cart. Remove from Cart. Customer Reviews I could find gems and information about them easily. Verbena, July, Source: Bizrate. Austin, July, Source: Bizrate. Matty, July, Source: Bizrate.

Tk, July, Source: Bizrate. Steve B. MrRich, July, Source: Bizrate. English speaking customer support only. GemSelect's Telephone numbers. Update Translation. Diamonds can be colored blue or yellow by the addition of impurities. The role of impurities in causing color is different here see semiconductors. Through yet another mechanism see charge transfer , the addition of impurities to corundum can produce a deep blue sapphire.

This can be because of a so-called crystal-field or, alternatively, a ligand-field effect. In this crystal field or ligand field effect, the field exerted by the host crystal on the guest impurity fixes the energy levels of the latter as a photon absorber.

Put another way, the chemical bonding between the host crystal and guest impurity always involves the donation of electrons from the host crystal to empty energy levels in the metal impurity, binding the metal to the crystal. Crystal field theory makes assumptions that are not very realistic, yet it gives surprisingly good qualitative results.