Not many investors have probably heard of perlite, a naturally occurring amorphous volcanic glass which expands by up to ten times when heated and because of this property is used for cavity wall insulation and aerating soil.
But it is a mineral that made Sunrise Resources Plc (LON:SRES) one of this week's biggest small cap gainers.
Sunrise shares surged by 55% to 0.21p after it revealed on Friday that it had signed a non-binding memorandum of understanding (MOU) that will pave the way for the first sales of perlite from its CS Pozzolan-Perlite project in Nevada, USA.
The miner said the unnamed purchaser - a long established buyer and processor of raw perlite - would provide commercial and logistical support and advice during the development of the perlite deposits on its CS and NewPerl Projects.
It also said the purchaser would make its production plant available to the projects for commercial scale testing.
Patrick Cheetham, executive chairman of Sunrise, said: "This is a significant step forward for the Company and a key value driver for the CS Project."
He added: "The market for horticultural grades of perlite is particularly strong and we look forward to working with the Purchaser to bring the project into production."
Broadband providers are undoubtedly more familiar ground for investors, and a small one of those, CityFibre Infrastructure Holdings PLC (LON:CITY) was the week's biggest AIM riser,.
Its shares jumped 94% in value to 79.4p after agreeing to be taken over by Connect Infrastructure Bidco Limited, a company formed by two private equity firms - Antin Infrastructure Partners UK and West Street Global Infrastructure Partners III.
The offer price of 81p per share represented a 92.9% premium on the closing price on 23 April, the day before the bid was revealed, and valued the company at around ?537.8mln.
The move came as CityFibre said it was making strategic progress in 2017 despite its profit falling on higher costs.
Elsewhere, Feedback plc (LON:FDBK) also had a very strong week, jumping 86% to 2.8p after posting two bits of good news.
On Wednesday the medical imaging company's stock soared on news it has secured a software licence and distribution agreement for its TexRAD technology with US conglomerate General Electric's Healthcare unit..
Feedback said the agreement granted GEHC non-exclusive global rights to offer Feedback's TexRAD texture analysis software for medical imaging research applications.
Then, on Friday, Feedback announced that a subsidiary company had signed a two-year agreement with Royal Papworth Hospital NHS Foundation Trust to support and maintain its Cadran picture archiving communication system.
Cadran is installed in a number of NHS sites in the East of England and represents an unseen but vital part of medical imaging, allowing scans to be easily stored, retrieved and analysed by medical practitioners to better diagnose disease and assess patient management.
Contract news also gave a boost this week to driver mentoring group Seeing Machines Limited (LON:SEE), which gained 27% to 5.8p after winning a deal with an original equipment manufacturer in the German car industry.
The unnamed company wants to incorporate Seeing Machines' FOVIO driver monitoring technology into new models planned for mass production from 2021.
And Tern PLC (LON:TERN) saw its shares climb by 44% to 17.13p this week after Device Authority, a company in which it holds a 56.8% stake, revealed a support deal for Microsoft Azure's Internet of Things (IoT) Hub.
The announcement followed the release of DA's KeyScaler 5.8 product, a global leader in Identity and Access Management for IoT.
The group said combining these two technologies will allow customers to take advantage of automated enterprise IoT security lifecycle management, as well as KeyScaler's Delegated Security Management model, which provides device provisioning with continued device lifecycle credential management.
Overall, the FTSE AIM All-share index edged 0.1% higher over the week to around 1,047, underperforming bigger gains by the blue-chip FTSE 100 index, which added 1.5% at around 7,471.
Weatherly International plc(LON:WTI) was the week's major small cap casualty, with its shares slumping by nearly 71% to 0.2p after the miner revealed on Thursday that it is unlikely to generate sufficient surplus cash to repay loans owed to Orion Mine Finance.
As a result, the group said, its ongoing strategic review, which was part of negotiations to restructure its debt facilities, could now lead to the sale of the entire company.
Earlier in the week, Weatherly also announced that it had failed to agree to an extension to the backstop date to purchase the Kitumba project in Zambia.
The AIM-listed miner said its negotiations with Intrepid Mines Limited regarding the sale had been unsuccessful and thus the agreement for the acquisition had lapsed.
Another big faller this week was Safestyle UK PLC (LON:SFE), which saw its shares plummet by 31% to 56.9p after warning on Monday that it expects underlying pre-tax profits to be "significantly below current market expectations".
The double glazing group also revealed that its non-executive chairman Steve Halbert had resigned from the board with immediate effect.
GBGI Limited (LON:GBGI) took a big tumble too this week, with its shares shedding 21% at 87.5p after the small cap insurance group saw its 2017 profits reduced by impairment charges of US$12.3mln from its operations in Angola.
The AIM-listed firm reported pre-tax profits of US$3.6mln, down from US$11.2mln a year earlier despite a revenue increase to US$155.9mln, up from US$35.9mln last year.
Net claims paid grew to US$62.5mln from US$37.4mln the year before while administrative expenses rose to US$53.9mln from US$35.9mln the year before, GBGI said.
Meanwhile, Paragon Entertainment Limited (LON:PEL) saw its shares tumble by 28% to 1.4p after it announced the start of a ?150,000 restructuring programme.
The AIM-listed attraction designer said, due to major cost overruns on two large projects, underlying earnings for the year were expected at ?200,000 on revenues of ?14.7mln.
With slower trading expected to have a knock-on effect in 2018, the group said it would begin restructuring immediately with a view to achieving annualised cost savings of ?400,000.
And localisations services provider RWS Holdings PLC (LON:RWS) dropped 18% to 371p as it warned that profit outcomes for the first half of the year will be "slightly" below market expectations".
The latest caution followed an announcement in February when the group said exchange rate headwinds had impacted its pre-tax profit forecasts.