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We know three main classes of rocks, sedimentary, igneous, and metamorphic. In the Limestone article, we learned how sedimentation occurs and the formation of sedimentary rocks takes place. Today, we are going to know Obsidian rock, which falls in the main class of igneous rocks.

We know igneous rocks have two basic types:

1. Intrusive Igneous Rocks

When molten lava/magma is cooling slowly below the surface of the earth and forms large crystals in the rocks, they are known as intrusive igneous rocks. For example-

  • Diorite
  • Gabbro
  • Granite
  • Pegmatite
  • Peridotite

2. Extrusive Igneous Rocks

When molten magma is cooling rapidly onto the surface of the earth and forms small crystals in the rocks, they are known as extrusive igneous rocks. For example-

  • Obsidian
  • Andesite
  • Basalt
  • Dacite
  • Pumice
  • Rhyolite
  • Scoria
  • Tuff
  • Fire Opal
 
 
 

What Is Obsidian Rock?

Obsidian is a glassy igneous rock that comes in a wide range of colours and textures. It forms when felsic lava extruded from a volcano onto the surface of the earth.

The cooling of lava takes place so rapidly that no chance remains for proper crystallization (Atomic Arrangements) and finds as an amorphous glass material. It has a smooth and uniform texture, which breaks with a conchoidal fracture.

Geological Classification of Obsidian Rocks:

Let’s see the classification of obsidian rocks from the perspective of a geologist.

  • Class: Igneous Rocks 
  • Sub-Class: Medium Hardness Rocks
  • Family-Group: Volcanic
  • Category: Opaque Rocks
  • Alternate Names: Lava, Glassy Lava, Xaga, Royal Agate, Glass Agate, Volcanic Glass, Glass Gem, Guardian Gem, and Black Beauty

Formation of Obsidian Rocks in Nature

We have seen in the earlier section that obsidian is a type of extrusive rock. It forms on the surface of the earth when magma or lava comes out due to volcanic phenomena and rapid cooling takes place. Obsidian rock can form in a variety of cooling environments such as-

  • Along the edges of a flow of magma or lava
  • Along the edges of a dome of the volcano
  • Along the edges of a sill or dike, which takes place under the surface and it is the only intrusive type
  • The point where magma comes into contact with water on the surface
  • The point where magma cools due to airborne cooling effects

Properties of Obsidian

Obsidians have various physical & visual properties, such as Hardness, Grain Size, Fracture, Streak (Colors), Porosity, Luster, and Strength. These all property attributes determine the applications of obsidian rocks. Let’s see some significant properties of obsidians.

Specific Gravity & Density of Obsidian

The density of rock is used to express specific gravity. It is measured in relevance to the density of water in gram per cubic centimeter of the mass. The density of obsidian is 2.55 g/cubic cm. It means it is heavier than water and dense medium as a mass.

Streaks & Colors of Obsidian

The streak of obsidian is white, but various colors occur in nature.

Frequently found colors of Obsidian rocks are:

The highest occurrence of obsidians is in Black, but it is also available in Brown, Green, or Tan.

Rarely found colors of Obsidian rocks are:

A very rare occurrence of obsidians is Blue, Orange, Red, and Yellow.

The occurrence of color is due to the presence of different trace elements in obsidian rocks.

Compressive Strength of Obsidian

When a compressive pressure (In Newton unit) is applied to the rocks, a permanent deformation of rocks takes place at a point of pressure. It is termed as the compressive strength of rocks and obsidians fractured or permanently deformed at 0.15 N per square millimeter. It means obsidian is easy to break and chipped by some impacts. It also renders obsidian the unfit stone for rings and bracelets like jewelry production.

Obsidian Fracture

Obsidians break into the conchoidal fracture. Obsidian has no natural or defined planes of separation when a pressure exceeding its physical strength exerts on it. Therefore, smoothly curved fracture takes place on the surface of obsidian glass rock.

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Grout haze is a milky white film that forms on the surface of the tiles after they have been installed and grouted. Many people often grab a sponge to remove grout haze after noticing it. They believe this will remove any extra grout left behind, only to have the milky white film resurface. Just when you thought you had spent enough time on your hands and knees cleaning up what you could see, the reality surfaces.

As the grout job dries, small particles leave a haze. This last sliver of grout byproduct requires extra care and elbow grease. Something that once appeared an easy matter to clean up now necessitates additional cleaning to eliminate the residue.

 

Why Grout Haze Forms Over Tiles?

You wash away the extra grout with a sponge after grouting your tiles. However, a small amount of grout is sometimes left behind, resulting in a yellowish haze. It is possible that you might not see it right away, especially if the tile is still wet. The haze often emerges after it has dried. After installation, you have a few options to remove any leftover grout from ceramic tile. Acting quickly usually yields the best results. Grout haze can form over porcelain, ceramic, or natural stone tiles. The durability of natural stone tiles allows you to remove grout haze without any major difficulties.

4 Easy Ways To Remove Grout Haze

Wipe The Tile With Dry Cheesecloth

In some conditions, removing haze from newly laid tiles could be as simple as wiping them with a dry cheesecloth. The sooner you do this after grouting your tile, the more effective it will be. However, you must first allow the grout to dry for at least 24 hours. This procedure will work if the grout haze is caused by loose or readily removable grout on the tile surface. After loosening the grout with the cloth, sweep or vacuum away the leftovers to clean the floor or counter.

Rub With a Damp Towel

If a dry cheesecloth is not working, try soaking it in plain water and wringing away the excess. The material should be damp but not dripping wet. Gently rub each tile with a bit of elbow grease to remove grout haze. The humidity can occasionally reactivate or moisten the grout on top of the tiles, making them easier to remove. You can also use a damp sponge to complete the task.

Diluted Vinegar Mixture

If water is not enough to clean smooth porcelain or ceramic tiles, vinegar is an option. However, do not use it on any stone, slate, or other porous tile material, since the vinegar's acidity may damage the tiles. Combine four parts of water and one part white vinegar to use on porcelain or ceramics. Use a delicate cloth dipped in the vinegar mixture and wipes the tiles with it. If necessary, add more vinegar to make the mix stronger. To eliminate any residual vinegar, wash the tiles with normal water once the rubbing is done.

Use The Grout Haze Remover

If you are still struggling with hazy grout leftovers on paver patterns, it is time to switch to a grout haze remover. Epoxy grout haze often necessitates using a product specifically designed for that type of grout. Many grout remover chemicals are acidic; hence they do not work well with natural stones and might damage them. Acidic cleaners can etch your new tile. Always use a grout haze remover specifically designed for the tile you have installed.

When utilizing chemical cleansers, make sure you work in a well-ventilated location. You can obtain additional protection by wearing a mask and gloves. Depending on the product, you may need to spray or wipe the cleaner onto the tile. Follow the packaging instructions for using the remover.

 

Tips To FollowBefore You Remove Grout Haze