You can get to the Earth Cache site a number of different ways. The easiest access point is the main National Park entrance at Teluk Bahang, for which we have provided the waypoint. From here, you can walk (around an hour and a half fairly strenuous walk each way) to Pantai Kerachut, or take a ride in a boat (RM100 for 2 people each way, 20 minutes). Both directions by boat, with 30-45 minutes at Pantai Kerachut and a stop at Turtle Beach on your return trip, will take 1.5 - 3 hours, depending on how long you choose to stay at each beach. You can also mix it up, and walk one direction and take a boat for the other part of the trip. Motorcycles and bicycles are not allowed in the National Park.
Quartz is an igneous rock made from silicon and oxygen atoms. It has a crystalline structure, and the crystals are large and often clearly visible. Quartz is the second-most common mineral in the Earth's crust. Pure quartz is transparent and colourless, but impurities (such as iron, manganese, aluminium or titanium), can cause quartz to take on various colours. Some of these transparent coloured stones are semi-precious gems, such as amethyst, which is quartz with a purple colouring due to the impurities. Jasper, citrine and onyx are also variant of quartz. Quartz is often found in pinks, blues, yellows, browns and pinks. Milky quartz is white and milky in appearance, and is not transparent because gases or liquids were trapped in the quartz as it cooled and the crystals were forming.
At the listed co-ordinates, you will find yourself standing on a rocky shoreline. It is possible that most of the quartz veins will be underwater during the highest spring tides, so do not come at these times. The large mass of rock on which you stand is a greyish-brown colour, but is criss-crossed by narrow lines of quartz that stand out due to their much different colouring. These narrow veins also stand up higher than the rock around them, so you should be able to identify them easily.
Quartz veins like the one here, probably are formed by the following sequence. The large mass of rock was formed when lava flowed here from a volcanic eruption long, long ago. As the lava cooled, it shrank, and cracks formed. Some time later, very hot water rose through these cracks, from deep below the surface of the earth. This hot water had minerals dissolved in it, which were gradually deposited on the sides of the cracks in the rock. The silicon and oxygen formed crystals of quartz in the fissure, gradually filling the crack with quartz. The surface of the rock has since been worn away by erosion, a gradual weathering process. Because the grey rock weathered faster than the quartz, the quartz sticks out higher than the surrounding rock.
When quartz crystals form quickly, they are more likely to trap water or gases, resulting in milky quartz. When crystal growth is slower, the resultant quartz is clearer. "Massive quartz" is quartz where the crystals are formed so close together, they form a solid block of rock, and the individual crystals become indistinguishable.
Questions
Find some of the quartz veins, and answer these questions, then email your answers to the cache owner.
1. Describe the quartz that forms the veins. Why do you think it looks like this?
2. Explain the direction of the veins and why you think they run this way.
3. Measure one of the average-sized veins. How wide is it (in millimetres)?
4. What is the widest vein you can see here?
5. Find some quartz crystals. How long are the biggest crystals? Why do you think there is a hollow between some of the crystals?
NOTE: If you forget to bring a ruler, here is a cheat's way to estimate sizes. Take a photograph of the rock you want to measure, and include in the photo an object of similar size. When you get back to "civilization", measure the object (for example a coin or matchstick), then you can estimate the size of the thing in the photo.
AND ANOTHER NOTE:We believe that the objective of an Earth Cache is to learn about geology whilst having fun in the outdoors. Finding "correct" answers is not as important as trying to understand the world around you. We encourage anybody to have a go and attempt this Earth Cache, and welcome all answers that have had some effort and thought put into them, whether they are "correct" or not. If you would like the answers sent to you, mention so in your email to the cache owner.
REFERENCES
http://www.quartzpage.de/gen_occ.html#VQ
https://www.geologyin.com/2014/11/veins-and-hydrothermal-deposits.html
https://en.wikipedia.org/wiki/Quartz