will heated sugar and water mix make an acid to dissolve quartz?
greenish colouration of quartz is uncommon, it may be a beryl, if slightly brown-orange it may be rutile. as quartz is commonly the last mineral to crystallise it often contains inclusions of other minerals
It is common and is called an inclusion. It is found in crystals, and various other forms of rock.
It's most likely some form of green chlorite inclusion, in a pure state it looks like a green tinge or haze, however if it appears mossy or with a solid form it could be any number of chlorite included minerals. There are a few other possibilities but chlorite is most likely and yes it is a fairly common occurrence for quartz crystals to have other crystals or various colored inclusions inside.
