Larger | Spin | 3D. Indium foil. Indium is often used to form air-tight seals between glass components because it is soft enough to mold itself to the shape of the glass, and because unlike rubber or other organic seal materials it is really 100% gas-tight and it doesn't release volatile compounds of its own.
Melasma is a chronic skin disorder that results in symmetrical, blotchy, brownish facial pigmentation. It can lead to considerable embarrassment and distress. This form of facial pigmentation is sometimes called chloasma, but as this means green skin, the term melasma (brown skin) is preferred.
1 Melasma is very common skin ailment. It can occur to anyone, but young women with brownish tone are more likely to contract with it.  The condition is often linked with female hormonal changes. Change in level of estrogen and progesterone may cause melasma.