A good ruby simulant could me made from _.
1) spinel
2) red corundum
3) molten Aluminum Oxide
4) Rubies can’t be simulated, only synthesized
5) heat treated low-quality rubies
The Correct Answer and Explanation is:
The correct answer is 1) spinel.
Explanation:
A ruby simulant is a material that mimics the appearance of a ruby, but is not chemically the same. Rubies are a variety of corundum (Al₂O₃), and their red color comes from trace amounts of chromium. When looking for a good ruby simulant, we are seeking materials that resemble the physical properties (color, transparency, luster) of rubies but do not have the same chemical composition.
Spinel is a commonly used ruby simulant. It is a naturally occurring gemstone composed of magnesium aluminate (MgAl₂O₄), which can have a deep red color similar to that of a ruby due to the presence of trace iron or chromium. Spinel is often used as a simulant because it has a similar appearance and hardness to rubies (it ranks around 8 on the Mohs scale of hardness, while ruby is a 9). Although spinel does not have the exact same optical properties as ruby (such as refractive index or dispersion), it is a popular choice in jewelry due to its affordability and color variety. In fact, red spinels were historically mistaken for rubies, especially before advanced gemological techniques were developed.
Other Options:
- 2) Red corundum: This is actually a ruby itself, as rubies are a variety of red corundum. Thus, it cannot be used as a simulant.
- 3) Molten Aluminum Oxide: This refers to the chemical composition of corundum (including rubies), but in molten form, it would not resemble a ruby until it solidifies and forms crystals. Even then, it would be corundum, not a simulant.
- 4) Rubies can’t be simulated, only synthesized: This is incorrect. While rubies can be synthesized in labs (using methods like flux or high-temperature fusion), they can still be simulated by other materials like spinel, garnet, or glass. Simulation and synthesis are different concepts—synthesis refers to creating a true ruby, while simulation refers to creating a look-alike.
- 5) Heat treated low-quality rubies: Heat treatment is used to enhance the color or clarity of natural rubies, but this does not create a simulant. It is still a ruby, just improved in quality.
In conclusion, spinel is one of the best and most historically significant ruby simulants, and it is widely used in the gem industry.