Ruby Overview Ruby Knowledge

The English name for Ruby is Ruby, which is derived from the Latin Ruber, meaning red.

The chemical composition of ruby ​​is aluminum oxide (Al2O3), which is red to purple-red due to the trace element chromium (Cr3+). (Note: Pink corundum is not called ruby, but pink sapphire.)

Only the red corundum colored by Cr can be called ruby. The pink corundum is not Cr-colored.

Crystal system: is a trigonal system.

Crystal habit: Crystal form is often barrel, short column, plate and so on. The aggregates are mostly granular or dense blocks.

Transparency: transparent to translucent,

Gloss: Bright glass luster to yam diamond.

Refractive index: 1.762-1.770, (+0.009, -0.005)

Birefringence: 0.008 to 0.010.

Dispersion: low 0.018

Polychromaticity: obvious dichroism, often expressed as: purple red/maroon, deep red/red, red/orange, rose/pink

Sex: U—(one-axis crystal negative).

Special optical effect: the starlight effect, which reflects the fascinating six-shot star or the twelve-shot starlight under the illumination of light, the color change effect

The Mohs hardness is: 9, so only diamonds can be scored on the surface. With one of its edges, it is easy to draw a line on the surface of the glass (the hardness of the glass is below 6);

SG (relative density): 3.99-4.00

Cleavage: no cleavage, bottom crack development.

Luminescence: Ruby emits red and dark red fluorescence under long- and short-wave ultraviolet radiation.

Absorption spectrum: A typical absorption spectrum of Cr. The 688nm690nm absorption double-line 668nm659nm absorption line is absorbed by the broadband absorption center (absorption of the yellow-green region) centered at 550nm and the 476nm475nm468nm purple region is absorbed.

The crack is more developed, and the common ruby ​​has many cracks inside it, which is called “ten red and nine cracks” of rubies;

It has obvious dichroism, and sometimes the color of the eye can be seen from different angles; the original ruby ​​before processing is barrel-shaped and plate-shaped.

Natural rubies are mostly from Asia (Myanmar, Thailand and Sri Lanka), Africa and Australia, and there is also a bit in Montana and South Carolina. Natural rubies are rare and rare, but man-made rubies are not too difficult, so industrial rubies are artificial.