Rasulullah SAW bersabda, “Siapa yang membaca selepas habis solat, Subhanallah 33 kali, Alhamdulillah 33 kali, Allahu Akbar 33 kali, lalu untuk mencukupkan bilangan seratus dengan membaca “Laa ilaaha illallah wahdahu laa syariika lahu, lahul-mulku walahul-hamdu wahuwa ‘alaa kulli syai’in qadir” maka akan diampunkan dosa-dosanya walaupun sebanyak buih air laut.” (HR Muslim)
Why are there so many colors of minerals?
We share a whole lot of mineral images on this page, many of which would qualify as gemstone if the stones are pristine enough. One great question for anyone who deals with minerals or gems is…where does the color come from?
Many minerals, when they are pure, are either completely colorless like quartz, or a single strong color, like hematite which will be dark black when found as a chunk. But on the other hand, there are minerals like corundum (aluminum oxide) which can be colorless, bright red as a ruby, blue as in a sapphire, or even pink and orange as in the rare Padparadschah.
The scientific definition of a mineral is that it is a solid substance found in nature with an atomic structure that is consistent and repetitive over a distance. In other words, it is a crystal made up of atoms put together in a constant sequence.
The key to the color for many minerals, as explained in this chart, is found in that setup. A single crystal is made up of a huge number of atoms. Sometimes, when a crystal grows, it can substitute the wrong atom into a spot; iron going into quartz for the silicon atom or chromium going into corundum in place of aluminum.
These impurities can fit into spots in crystals some, but often not perfectly. They may vibrate around or they may bond incorrectly with the surrounding oxygen atoms, changing how the electrons in the structure join together.
Electrons are the keys to color. When electrons are able to move within the structure of minerals, they are able to absorb light and create colors that we are able to see.
This chart outlines how color forms in many common minerals and gemstones. Almost all of them follow a certain format; the wrong element goes into a crystal in a small amount, creating unpaired or mobile electrons that interact with light passing through the crystal structure.
Image credit: Compound Chemistry (creative commons license): http://www.compoundchem.com/2014/06/29/what-causes-the-colour-of-gemstones/
writing is hard
Know your tasks: organize your study material and schedule so you know exactly what chapters or lectures you need to review. If possible, set a to-do list as specific as you can and go checking it as you progress. Seeing how much you’ve completed will motivate you to keep going!
Keep distractions away: if you’re easily distracted by your phone, keep it away while you study. If background noise is a problem for you, try headphones or listening to instrumental music to help you focus. Find what distracts you and save it for another time.
Have a healthy diet. It’s important to drink plenty of water and eat nutritious food so your body can work properly. Certain nutrients like Omega 3 can help your memory and can be found in oily fish, like salmon. Vegetables and fruits contain carbs and fiber which will give you energy and caffeine - from coffee or tea - is extremely useful, as we all know.
Take frequent breaks, and use this time to get moving, stretch, go outside, talk to people. I particularly think exercising works fantastically because it keeps you awake and concentrated.
Make summaries. If you’re not distracted by using a computer try to make a digital one so you save time. You can later print it and use this to help you revise. It also helps you stay focused while you read. You can make your own diagrams as well for better visualizing and understanding of processes, cycles, etc.
Make flashcards or take phone pics of important diagrams so you can revise key concepts at the bus or while you’re waiting for someone. Challenge your memory!
Don’t hesitate to ask for help. Whether being from a tutor or simply your friends, having someone answer your questions or explain something to you can be very helpful. You get a different perspective about the subject, see how other people learn (maybe they have great mnemonic strategies you didnt know!) and get to be more interactive. Also, on the other hand, when you explain something to someone it’s easier to spot your own mistakes and doubts and it helps retaining what you studied in long term memory.
Set a routine. Try your best to wake up and go to bed at the same time everyday and keep an organized schedule (even if its in your mind or your phone). That way you have separate times to study, workout, sleep well and avoid wasting time, arriving late, having to pull all nighters, missing when your papers are due to.
Spend more time at libraries. A library generally has more comfortable study places than you do at home, you’re surrounded by people who are also studying, there’s fairly a lot less to be distracted about, books are easily accessible and in most cases you’d be near labs or your teachers offices in case you want to go to that lab review or ask something. You also are less likely to turn your 20 min nap into a 4 hour blackout because sleeping over your books is just not that comfortable.
Don’t stress. Pulling all nighters, having emotional breakdowns or just generally panicking over exams and papers is just not worth it. In most cases what you fear about those things never happen. You’re going to be okay, even if you fail. Because there are always second chances, especially if you’re dedicated. Most successful people I know got that far through perseverance. Which is something you learn when you fail, but refuse to stop trying nonetheless.
Cats can be bros sometimes.
Para calon ibu atau yang udah jadi ibu wajib baca nih! :D
Halong Bay, Vietnam - One of the best examples of tower Karst in the world
Halong Bay was formed through the dissolution of limestone millions of years ago, forming a perfect geological example of karst topography.
As rainwater collected carbon dioxide from the atmosphere, slightly acidic rainwater containing small amounts of carbonic acid were capable of eating away at the limestone, forming these towers and islets located in Halong Bay. This is a classic example of Karst’s dissolution mechanism. This rain water made its way into the natural cracks and crevasses of the rock, and eventually widened the rock over the course of millennia into caves, tunnels, and bays. This process was amplified in the Vietnamese tropical region. Due to the extra vegetation, the rainwater absorbed extra carbon in its seeping path through the rock, becoming more acidic and better developing this karst environment, making this one of the best visible karst environments in the world.
The visible limestone today has existed for nearly 500 million years. Its first 100 million years of life was spent deep under the ocean, but uplift moved it into a shallow sea environment for an additional 150 million years. Sea level fluctuations allowed for the surfacing of many of these subaqueous limestone formations, allowing for the Karst features seen here. It is for this reason that many of the developed karst regions are underwater, unable to be seen. Now smothered by water from the melting of the last ice age, many unseen valleys and drowned Karst formations remain hidden.
Over the years, more limestone has been eroded than exists today. Halong Bay faces environmental danger today, as mangroves and seagrass beds are being cleared for tourist boats. Fuel and oil have created pollution problems, and portable toilets created for tourists have polluted the surrounding soil and water. Many additional dangers pose a threat to the continued existence of this geological treasure. Hence, efforts are being made to preserve Vietnam’s Halong Bay.
Image Credit: Lonely Planet