Ingredients: mainly silica
Hardness: 5
Proportion: 2.35
Refractive index: 1.48-1.51
It is a kind of natural glass which is formed after the volcanic lava is rapidly cooled, so it is difficult to crystallize. Amorphous, without cleavage, the fracture is shell-like. It is usually black, but it can also be seen in brown, gray and a small amount of red, blue and green materials. The color may be monochromatic, or striped, or speckled. Some inclusions make obsidian metallic, while internal bubbles or crystals produce a "snow" effect (ie, snowflake obsidian) or a rainbow color that is seen as a flash.
Origin: Distributed in areas with or without volcanic activity, such as Hawaii, Japan, and Indonesia in the United States. Others include the Lipari Islands near Iceland, Hungary, and Italy, the former Soviet Union, Mexico, Ecuador, and Guatemala. Dark TB is distributed in Arizona and New Mexico (USA) and is known as "The Tears of Apache."
These KN95 masks have the following features:
Complies with KN95 standards for CDC NPPTL Respirator Assessments to Support the COVID-19 Response
3-layers of Protection: Uses a triple layer of melt-blown nonwoven material to block 95% of incoming particulates.
Secure Seal: The adjustable nose piece provides a secure seal. Easy Breathing: Advanced non-woven fabric is easy to breathe through.
Comfortable Design: Made with durable elastic straps and a skin-friendly, soft non-woven fabric optimized for long periods of wear
Note
If the mask is damaged or soiled, or if breathing becomes difficult, remove the mask, discard it properly.
Keep the storage area dry at room temperature.
This mask may not eliminate the risk of all diseases and infections.
This mask must be sealed properly, misuse can result in higher risk
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