A good ruby simulant could be made from _.
spinel
red corundum
molten Aluminum Oxide
Rubies can’t be simulated, only synthesized
heat treated low-quality rubies
The Correct Answer And Explanation is:
The correct answer is: spinel
Explanation (300+ words):
Rubies are a variety of the mineral corundum, which is composed primarily of aluminum oxide (Al₂O₃) with trace amounts of chromium that give rubies their distinctive red color. Because natural rubies are rare and expensive, alternatives have been developed for use in jewelry. These alternatives fall into two main categories: synthetic rubies and simulants.
Synthetic rubies are chemically identical to natural rubies (they are also aluminum oxide with chromium), but they are man-made in laboratories using methods like flame fusion or the Verneuil process. In contrast, simulants are different substances that only mimic the appearance of a ruby but do not share the same chemical composition or physical properties.
One of the most historically significant and common ruby simulants is spinel. Natural and synthetic spinel can have a deep red color that closely resembles ruby, and it has often been mistaken for ruby in antique jewelry. In fact, some famous “rubies,” such as the Black Prince’s Ruby in the British Crown Jewels, were later identified as red spinels.
Spinel (MgAl₂O₄) is a different mineral from ruby, though it is also composed of aluminum and oxygen, along with magnesium. Its crystal structure, hardness (around 7.5–8 on the Mohs scale), and appearance make it a suitable simulant, though it is softer and less durable than ruby (which ranks 9 on the Mohs scale).
Let’s look at the incorrect options:
- Red corundum is actually a ruby, not a simulant.
- Molten aluminum oxide is a starting material for synthetic ruby, but not itself a simulant.
- The statement “Rubies can’t be simulated, only synthesized” is incorrect. Rubies can be simulated using materials like spinel and even colored glass.
- Heat-treated low-quality rubies are still real rubies—they are enhanced, not simulated.
Therefore, spinel is the best answer for a ruby simulant.