Why is ice water white, others clear?

Why does the phenomenon of some ice cubes have a white color while others are as clear as mirrors?

When you put some ice cubes (taken from your refrigerator) into a drink at home, you can see that they are mostly opalescent like clouds. However, surely you also see other stones (especially in high-end bars and restaurants) like this:

Transparent stones.

You may think this phenomenon is related to the quality of water used to freeze but this is not necessarily true. In fact, you can get some water (which can be drunk immediately) and test yourself by adding this amount to the refrigerator to freeze. Most likely you will see the opaque stones afterwards, no matter how good your ice maker is. Even the stones you make are not as good as you see in a bar or restaurant.

The same volume of water, the freezing process is the same but why is there a difference in appearance between the stones that were created like that? Below is an explanation according to ScienceABC.

Why are some stones opaque while others are transparent?

Stone at home is often white like this.

Short answer: Although the water has an undisputed effect on the appearance of the stones, the temperature used is the most important factor leading to transparent or colored stones. opalescent. At room temperature, water-soluble impurities are not visible, but when the water is cooled, they accumulate to create chiseled stones.

Water at room temperature contains many impurities

Although we do not see with the naked eye, the water we drink contains some impurities. You should note that "impurities" do not always mean bacteria and bacteria, anything other than water found in water is called "impurities". Tap water contains a lot of impurities but most of them are not harmful to us. In fact, some of them (such as calcium and magnesium) really benefit our health. Different impurities also bring the characteristic flavor to the water.

When water freezes, impurities distributed evenly in the water tend to gather in the middle (core) of the stone.

The most common impurities found in tap water include lime, calcium, fluoride, nitrate, magnesium and some other organic substances that are practically impossible to remove by conventional filtration methods. Therefore, when water freezes, impurities distributed evenly in the water tend to gather in the middle (core) of the stone.

Note: ice cubes made from distilled water are usually more transparent because they contain less impurities.

Ice cubes are often cloudy when quickly cooled

Even if you try to use boiled water to freeze ice, it may be that the ice cubes are not what you want it to be.

The reason is not related to how much impurities are water but how it is cooled.

You see, when you cool the water in the freezer, it will reduce the temperature quickly and the small air bubbles (formed from water-soluble air) are trapped in the crystal structure. These bubbles are then pushed towards the center of the cube when the water freezes around them.

You can use boiled water to cool slowly to create high-purity ice cubes.

In order to ensure that the stone blocks have a high transparency, professional stone producers use layer-by-layer freezing methods so that bubbles do not form in the stone. Furthermore, they freeze in very slow mode, so the air bubbles have time to escape the water block.

If you want, you can create high transparency ice at home. Just use boiled water (even boil 2 times for better results) and then cool slowly.